Symbol The symbol for composition is a small circle: (g º f) (x) It is not a filled in dot: (g · f) (x), as that means multiply. Composed With Itself We can even compose a function with itself! Example: f (x) = 2x+3 (f º f) (x) = f (f (x)) First we apply f, then apply f to that result: (f º f) (x) = 2 (2x+3)+3 = 4x + 9Bachelors. Here we asked to compute G composed with G of X, which means take the function G of X, plug it in for X in itself, so what we'll do is take two X plus 7 and plug that in for X in the function two X plus 7. So out comes the X in goes the two X plus 7. And there we will use parentheses appropriately because it is multiplication.Apr 30, 2011 · Apr 30, 2011. #2. the letter which you use to label a function has no special meaning. g (x) just identifies a function of x, in the same way as that f (x) does. Using a "g" instead of an "f" only means the function has a different label assigned to it. Typically this is done where you have already got an f (x), so creating another one would be ... What you called \times is called function composition, and is written (g ∘ f)(x) = g(f(x)). As you noted, it's not commutative, but it is associative. Whenever the compositions are defined, (h ∘ g) ∘ f = h ∘ (g ∘ f) = h ∘ g ∘ f. In a way, the function iteration can be extended to fractional exponents as well.(f+g)(x) is shorthand notation for f(x)+g(x). So (f+g)(x) means that you add the functions f and g (f-g)(x) simply means f(x)-g(x). So in this case, you subtract the functions. (f*g)(x)=f(x)*g(x). So this time you are multiplying the functions and finally, (f/g)(x)=f(x)/g(x). Now you are dividing the functions.A small circle (∘) is used to denote the composition of a function. Go through the below-given steps to understand how to solve the given composite function. Step 1: First write the given composition in a different way. Consider f (x) = x2 and g (x) = 3x. Now, (f ∘ g) (x) can be written as f [g (x)]. Step 2: Substitute the variable x that ...Function composition (or composition of functions) usually looks like f (g (x) ) or (f ∘ g ) (x), which both read as "f of g of x." To help us better understand function composition , let’s imagine we want to buy some merch, and we can use two coupons to bring down the original price . See full list on mathsisfun.com You could view this as a function, a function of x that's defined by dividing f of x by g of x, by creating a rational expression where f of x is in the numerator and g of x is in the denominator. And so this is going to be equal to f of x-- we have right up here-- is 2x squared 15x minus 8.Proof verification: if f,g: [a,b] → R are continuous and f = g a.e. then f = g. Your proof goes wrong here "The non-empty open sets in [a,b] are one of these forms: [a,x), (x,b], (x,y) or [a,b] itself..." That statement about open sets is just wrong. For instance, the union of ... 3) g(x)= f (x)−(mx+b)= f (x)−xf (1)+(x−1)f (0). Jan 26, 2017 · A function f (x) and g (x) then: (f + g) (x) = x² - x + 6. Further explanation. Like the number operations we do in real numbers, operations such as addition, installation, division or multiplication can also be done on two functions. Suppose a function f (x) and g (x) then: (f + g) (x) = f (x) + g (x) (f + g) (x) is a new function of the sum ... (f+g)(x) is shorthand notation for f(x)+g(x). So (f+g)(x) means that you add the functions f and g (f-g)(x) simply means f(x)-g(x). So in this case, you subtract the functions. (f*g)(x)=f(x)*g(x). So this time you are multiplying the functions and finally, (f/g)(x)=f(x)/g(x). Now you are dividing the functions.Graphs of Functions. This section should feel remarkably similar to the previous one: Graphical interpretation of sentences like f (x)= 0 f ( x) = 0 and f (x) >0. f ( x) > 0. This current section is more general—to return to the previous ideas, just let g(x) g ( x) be the zero function. If you know the graphs of two functions f f and g, g ...Share a link to this widget: More. Embed this widget ». Added Aug 1, 2010 by ihsankhairir in Mathematics. To obtain the composite function fg (x) from known functions f (x) and g (x). Use the hatch symbol # as the variable when inputting. Send feedback | Visit Wolfram|Alpha. Use this calculator to obtain the composite function fg (x) Set up the composite result function. g(f (x)) g ( f ( x)) Evaluate g(x− 2) g ( x - 2) by substituting in the value of f f into g g. g(x−2) = (x−2)+2 g ( x - 2) = ( x - 2) + 2. Combine the opposite terms in (x− 2)+2 ( x - 2) + 2. Tap for more steps... g(x−2) = x g ( x - 2) = x. Apr 30, 2011 · Apr 30, 2011. #2. the letter which you use to label a function has no special meaning. g (x) just identifies a function of x, in the same way as that f (x) does. Using a "g" instead of an "f" only means the function has a different label assigned to it. Typically this is done where you have already got an f (x), so creating another one would be ... It just means you've found a family of solutions. If you've got a one-to-one (Injective) function f(x), then you can always define its inverse g(x) = f − 1(x) such that f(g(x)) = g(f(x)). for example, consider f = x3 and g = 3√x. @KonstantinosGaitanas both f(g) and g(f) maps from the reals to the reals.The Function which squares a number and adds on a 3, can be written as f (x) = x2+ 5. The same notion may also be used to show how a function affects particular values. Example. f (4) = 4 2 + 5 =21, f (-10) = (-10) 2 +5 = 105 or alternatively f: x → x2 + 5. The phrase "y is a function of x" means that the value of y depends upon the value of ...Rule 3: Additive identity I don't know if you interpreted the definition of the vector addition of your vector space correctly, but your reasoning for Rule 3 seems to be a bit odd. f (x)+g(x)= f (x) f (g(x))= f (x) ... Since you already know that h is a continuous bijection, you need only show that h is an open map, i.e., that h[U] is open in h ...Nov 17, 2017 · The domain means all the possible values of x and the range means all the possible values of y. The functions are given below. f (x) = x. g (x) = 1. Then the domain of the function (g/f) (x) will be. (g/f) (x) = 1 / x. Then the graph of the function is given below. The domain of the function is a real number except 0 because the function is not ... Algebra Examples Popular Problems Algebra Simplify f (g (x)) f (g(x)) f ( g ( x)) Remove parentheses. f gx f g xgf(x) = g(f(x)) = g(x2) = x2 +3. Here is another example of composition of functions. This time let f be the function given by f(x) = 2x and let g be the function given by g(x) = ex. As before, we write down f(x) first, and then apply g to the whole of f(x). In this case, f(x) is just 2x. Applying the function g then raises e to the power f(x ...Mar 30, 2017 · Learn how to solve f(g(x)) by replacing the x found in the outside function f(x) by g(x). Which expression is equivalent to (f + g) (4)? f (4) + g (4) If f (x) = 3 - 2x and g (x)=1/x+5, what is the value of (f/9) (8)? -169. If f (x) = x2 - 2x and g (x) = 6x + 4, for which value of x does (f + g) (x) = 0? -2. The graphs of f (x) and g (x) are shown below. Composite functions and Evaluating functions : f(x), g(x), fog(x), gof(x) Calculator - 1. f(x)=2x+1, g(x)=x+5, Find fog(x) 2. fog(x)=(x+2)/(3x), f(x)=x-2, Find gof(x ...A function f (x) and g (x) then: (f + g) (x) = x² - x + 6. Further explanation. Like the number operations we do in real numbers, operations such as addition, installation, division or multiplication can also be done on two functions. Suppose a function f (x) and g (x) then: (f + g) (x) = f (x) + g (x) (f + g) (x) is a new function of the sum ...You could view this as a function, a function of x that's defined by dividing f of x by g of x, by creating a rational expression where f of x is in the numerator and g of x is in the denominator. And so this is going to be equal to f of x-- we have right up here-- is 2x squared 15x minus 8. It just means you've found a family of solutions. If you've got a one-to-one (Injective) function f(x), then you can always define its inverse g(x) = f − 1(x) such that f(g(x)) = g(f(x)). for example, consider f = x3 and g = 3√x. @KonstantinosGaitanas both f(g) and g(f) maps from the reals to the reals.Functions f and g are inverses if f(g(x))=x=g(f(x)). For every pair of such functions, the derivatives f' and g' have a special relationship. Learn about this relationship and see how it applies to 𝑒ˣ and ln(x) (which are inverse functions!).(f+g)(x) is shorthand notation for f(x)+g(x). So (f+g)(x) means that you add the functions f and g (f-g)(x) simply means f(x)-g(x). So in this case, you subtract the functions. (f*g)(x)=f(x)*g(x). So this time you are multiplying the functions and finally, (f/g)(x)=f(x)/g(x). Now you are dividing the functions. Algebra. Graph f (x)=|x|. f (x) = |x| f ( x) = | x |. Find the absolute value vertex. In this case, the vertex for y = |x| y = | x | is (0,0) ( 0, 0). Tap for more steps... (0,0) ( 0, 0) The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression ...A composite function is a function that depends on another function. A composite function is created when one function is substituted into another function. For example, f (g (x)) is the composite function that is formed when g (x) is substituted for x in f (x). f (g (x)) is read as “f of g of x ”. f (g (x)) can also be written as (f ∘ g ...What does (f ∘ g) mean in math? - Quora. Something went wrong. Wait a moment and try again.Mar 30, 2017 · Learn how to solve f(g(x)) by replacing the x found in the outside function f(x) by g(x). You could view this as a function, a function of x that's defined by dividing f of x by g of x, by creating a rational expression where f of x is in the numerator and g of x is in the denominator. And so this is going to be equal to f of x-- we have right up here-- is 2x squared 15x minus 8. The Function which squares a number and adds on a 3, can be written as f (x) = x2+ 5. The same notion may also be used to show how a function affects particular values. Example. f (4) = 4 2 + 5 =21, f (-10) = (-10) 2 +5 = 105 or alternatively f: x → x2 + 5. The phrase "y is a function of x" means that the value of y depends upon the value of ... What you called \times is called function composition, and is written (g ∘ f)(x) = g(f(x)). As you noted, it's not commutative, but it is associative. Whenever the compositions are defined, (h ∘ g) ∘ f = h ∘ (g ∘ f) = h ∘ g ∘ f. In a way, the function iteration can be extended to fractional exponents as well. Use of the Composition Calculator. 1 - Enter and edit functions f(x) f ( x) and g(x) g ( x) and click "Enter Functions" then check what you have entered and edit if needed. 2 - Press "Calculate Composition". 2 - The exponential function is written as (e^x). Solve your math problems using our free math solver with step-by-step solutions. Our math solver supports basic math, pre-algebra, algebra, trigonometry, calculus and more.Given that f(x)=9-x^2 and g(x)=5x^2+2x+1, Sal finds (f+g)(x). Created by Sal Khan and Monterey Institute for Technology and Education.Share a link to this widget: More. Embed this widget ». Added Aug 1, 2010 by ihsankhairir in Mathematics. To obtain the composite function fg (x) from known functions f (x) and g (x). Use the hatch symbol # as the variable when inputting. Send feedback | Visit Wolfram|Alpha. Use this calculator to obtain the composite function fg (x) A composite function is a function that depends on another function. A composite function is created when one function is substituted into another function. For example, f (g (x)) is the composite function that is formed when g (x) is substituted for x in f (x). f (g (x)) is read as “f of g of x ”. f (g (x)) can also be written as (f ∘ g ... Apr 29, 2017 · Besides being called (composition) commutative, it is sometimes also said that such functions are permutable, e.g. see here.As an example, a classic result of Ritt shows that permutable polynomials are, up to a linear homeomorphism, either both powers of x, both iterates of the same polynomial, or both Chebychev polynomials. f (x) = x f ( x) = x. Rewrite the function as an equation. y = x y = x. Use the slope-intercept form to find the slope and y-intercept. Tap for more steps... Slope: 1 1. y-intercept: (0,0) ( 0, 0) Any line can be graphed using two points. Select two x x values, and plug them into the equation to find the corresponding y y values.Purplemath. Composition of functions is the process of plugging one function into another, and simplifying or evaluating the result at a given x -value. Suppose you are given the two functions f(x) = 2x + 3 and g(x) = −x2 + 5. Composition means that you can plug g(x) into f(x), (or vice versa).For example, g(x) approaches 3 when x approaches 1, and f(3) = 10 but the function f(x) is discontinuous at f(3) such that the one side limits are different and hence its limit is undefined, will lim {x→1} f(g(x)) return the value 10?Step 1: Identify the functions f and g you will do function composition for. Step 2: Clearly establish the internal and external function. In this case we assume f is the external function and g is the internal formula. Step 3: The composite function is defined as (f g) (x) = f (g (x)) You can simplify the resulting output of f (g (x)), and in ...Example: f (x)=√x and g (x)=√ (3−x) The domain for f (x)=√x is from 0 onwards: The domain for g (x)=√ (3−x) is up to and including 3: So the new domain (after adding or whatever) is from 0 to 3: If we choose any other value, then one or the other part of the new function won't work. In other words we want to find where the two ...Example: f (x)=√x and g (x)=√ (3−x) The domain for f (x)=√x is from 0 onwards: The domain for g (x)=√ (3−x) is up to and including 3: So the new domain (after adding or whatever) is from 0 to 3: If we choose any other value, then one or the other part of the new function won't work. In other words we want to find where the two ...Bachelors. Here we asked to compute G composed with G of X, which means take the function G of X, plug it in for X in itself, so what we'll do is take two X plus 7 and plug that in for X in the function two X plus 7. So out comes the X in goes the two X plus 7. And there we will use parentheses appropriately because it is multiplication.Rule 3: Additive identity I don't know if you interpreted the definition of the vector addition of your vector space correctly, but your reasoning for Rule 3 seems to be a bit odd. f (x)+g(x)= f (x) f (g(x))= f (x) ... Since you already know that h is a continuous bijection, you need only show that h is an open map, i.e., that h[U] is open in h ... Functions f and g are inverses if f(g(x))=x=g(f(x)). For every pair of such functions, the derivatives f' and g' have a special relationship. Learn about this relationship and see how it applies to 𝑒ˣ and ln(x) (which are inverse functions!).f (x) = x f ( x) = x. Rewrite the function as an equation. y = x y = x. Use the slope-intercept form to find the slope and y-intercept. Tap for more steps... Slope: 1 1. y-intercept: (0,0) ( 0, 0) Any line can be graphed using two points. Select two x x values, and plug them into the equation to find the corresponding y y values.Free functions composition calculator - solve functions compositions step-by-stepMay 24, 2019 · It's a big theorem that all rational functions have elementary antiderivatives. The general way to integrate a rational function is to factor it into quadratics and linears (this is always possible by FTA), and use partial fractions decomposition. For our specific example, we have to factor x4 −x2 + 1 x 4 − x 2 + 1. There are rules we can follow to find many derivatives. For example: The slope of a constant value (like 3) is always 0. The slope of a line like 2x is 2, or 3x is 3 etc. and so on. Here are useful rules to help you work out the derivatives of many functions (with examples below ). Note: the little mark ’ means derivative of, and f and g are ... Algebra. Find the Domain (fg) (x) (f g) (x) ( f g) ( x) The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined. Interval Notation: (−∞,∞) ( - ∞, ∞) Set -Builder Notation: {x|x ∈ R} { x | x ∈ ℝ }Function composition (or composition of functions) usually looks like f (g (x) ) or (f ∘ g ) (x), which both read as "f of g of x." To help us better understand function composition , let’s imagine we want to buy some merch, and we can use two coupons to bring down the original price . Generally, an arithmetic combination of two functions f and g at any x that is in the domain of both f and g, with one exception. The quotient f/g is not defined at values of x where g is equal to 0. For example, if f (x) = 2x + 1 and g (x) = x - 3, then the doamins of f+g, f-g, and f*g are all real numbers. The domain of f/g is the set of all ...Mar 30, 2017 · Learn how to solve f(g(x)) by replacing the x found in the outside function f(x) by g(x). The Function Composition Calculator is an excellent tool to obtain functions composed from two given functions, (f∘g) (x) or (g∘f) (x). To perform the composition of functions you only need to perform the following steps: Select the function composition operation you want to perform, being able to choose between (f∘g) (x) and (g∘f) (x).Oct 18, 2015 · Solving for (f ∘ g )(x) watch fully. College Algebra getting to you? No worries I got you covered check out my other videos for help. If you don't see what ... Arithmetic operations on a function calculator swiftly finding the value of the arithmetic multiplication operation. Example 4: f (x)=2x+4. g (x)= x+1. (f÷g) (x)=f (x)÷g (x) (f÷g) (x)= (2x+4)÷(x+1) The quotient of two functions calculator is especially designed to find the quotient value when dividing the algebraic functions. In this video we learn about function composition. Composite functions are combinations of more than one function. In this video we learn about f(g(x)) and g...Operations on Functions. Functions with overlapping domains can be added, subtracted, multiplied and divided. If f(x) and g(x) are two functions, then for all x in the domain of both functions the sum, difference, product and quotient are defined as follows. (f + g)(x) = f(x) + g(x) (f − g)(x) = f(x) − g(x) (fg)(x) = f(x) × g(x) (f g)(x ...Equations with variables on both sides: 20-7x=6x-6. Khan Academy. Product rule. Khan Academy. Calculus 1 Lecture 2.2: Techniques of Differentiation (Finding Derivatives of Functions Easily) YouTube. Basic Differentiation Rules For Derivatives. YouTube. Algebra Examples Popular Problems Algebra Simplify f (g (x)) f (g(x)) f ( g ( x)) Remove parentheses. f gx f g xGiven two functions, add them, multiply them, subtract them, or divide them (on paper). I have another video where I show how this looks using only the grap...More formally, given and g: X → Y, we have f = g if and only if f(x) = g(x) for all x ∈ X. [6] [note 2] The domain and codomain are not always explicitly given when a function is defined, and, without some (possibly difficult) computation, one might only know that the domain is contained in a larger set.The Function Composition Calculator is an excellent tool to obtain functions composed from two given functions, (f∘g) (x) or (g∘f) (x). To perform the composition of functions you only need to perform the following steps: Select the function composition operation you want to perform, being able to choose between (f∘g) (x) and (g∘f) (x).More formally, given and g: X → Y, we have f = g if and only if f(x) = g(x) for all x ∈ X. [6] [note 2] The domain and codomain are not always explicitly given when a function is defined, and, without some (possibly difficult) computation, one might only know that the domain is contained in a larger set.You have f(x) =x2 + 1 f ( x) = x 2 + 1 and g(f(x)) = 1/(x2 + 4) g ( f ( x)) = 1 / ( x 2 + 4). Now pause and think about the second function. The function is defined as g(f(x)) g ( f ( x)), right. now what if there is some way that you could manipulate this function and some how change it to g(x) g ( x).Arithmetic operations on a function calculator swiftly finding the value of the arithmetic multiplication operation. Example 4: f (x)=2x+4. g (x)= x+1. (f÷g) (x)=f (x)÷g (x) (f÷g) (x)= (2x+4)÷(x+1) The quotient of two functions calculator is especially designed to find the quotient value when dividing the algebraic functions. Video transcript. - So we have the graphs of two functions here. We have the graph y equals f of x and we have the graph y is equal to g of x. And what I wanna do in this video is evaluate what g of, f of, let me do the f of it another color, f of negative five is, f of negative five is. And it can sometimes seem a little daunting when you see ...g(x) = x g ( x) = x. Rewrite the function as an equation. y = x y = x. Use the slope-intercept form to find the slope and y-intercept. Tap for more steps... Slope: 1 1. y-intercept: (0,0) ( 0, 0) Any line can be graphed using two points. Select two x x values, and plug them into the equation to find the corresponding y y values. In practice, there is not much difference between evaluating a function at a formula or expression, and composing two functions. There's a notational difference, of course, but evaluating f (x) at y 2, on the one hand, and composing f (x) with g(x) = y 2, on the other hand, have you doing the exact same steps and getting the exact same answer ...A function f (x) and g (x) then: (f + g) (x) = x² - x + 6. Further explanation. Like the number operations we do in real numbers, operations such as addition, installation, division or multiplication can also be done on two functions. Suppose a function f (x) and g (x) then: (f + g) (x) = f (x) + g (x) (f + g) (x) is a new function of the sum ...Oct 29, 2007 · Bachelors. Here we asked to compute G composed with G of X, which means take the function G of X, plug it in for X in itself, so what we'll do is take two X plus 7 and plug that in for X in the function two X plus 7. So out comes the X in goes the two X plus 7. And there we will use parentheses appropriately because it is multiplication. Apr 30, 2011. #2. the letter which you use to label a function has no special meaning. g (x) just identifies a function of x, in the same way as that f (x) does. Using a "g" instead of an "f" only means the function has a different label assigned to it. Typically this is done where you have already got an f (x), so creating another one would be ...That is, the functions f : X → Y and g : Y → Z are composed to yield a function that maps x in domain X to g(f(x)) in codomain Z. Intuitively, if z is a function of y, and y is a function of x, then z is a function of x. The resulting composite function is denoted g ∘ f : X → Z, defined by (g ∘ f )(x) = g(f(x)) for all x in X.
Equations with variables on both sides: 20-7x=6x-6. Khan Academy. Product rule. Khan Academy. Calculus 1 Lecture 2.2: Techniques of Differentiation (Finding Derivatives of Functions Easily) YouTube. Basic Differentiation Rules For Derivatives. YouTube.. 3 rooms for dollar99 stanley steemer
Step 1: Identify the functions f and g you will do function composition for. Step 2: Clearly establish the internal and external function. In this case we assume f is the external function and g is the internal formula. Step 3: The composite function is defined as (f g) (x) = f (g (x)) You can simplify the resulting output of f (g (x)), and in ...Set up the composite result function. f (g(x)) f ( g ( x)) Evaluate f (x2 −x) f ( x 2 - x) by substituting in the value of g g into f f. f (x2 −x) = 2(x2 − x)+1 f ( x 2 - x) = 2 ( x 2 - x) + 1. Simplify each term. Tap for more steps... f (x2 −x) = 2x2 − 2x+1 f ( x 2 - x) = 2 x 2 - 2 x + 1.y−gx = 1 y - g x = 1. This is the form of a hyperbola. Use this form to determine the values used to find vertices and asymptotes of the hyperbola. (x−h)2 a2 − (y−k)2 b2 = 1 ( x - h) 2 a 2 - ( y - k) 2 b 2 = 1. Match the values in this hyperbola to those of the standard form. The variable h h represents the x-offset from the origin, k k ... Composite functions and Evaluating functions : f(x), g(x), fog(x), gof(x) Calculator - 1. f(x)=2x+1, g(x)=x+5, Find fog(x) 2. fog(x)=(x+2)/(3x), f(x)=x-2, Find gof(x ...AboutTranscript. Functions assign outputs to inputs. The domain of a function is the set of all possible inputs for the function. For example, the domain of f (x)=x² is all real numbers, and the domain of g (x)=1/x is all real numbers except for x=0. We can also define special functions whose domains are more limited. The domain means all the possible values of x and the range means all the possible values of y. The functions are given below. f (x) = x. g (x) = 1. Then the domain of the function (g/f) (x) will be. (g/f) (x) = 1 / x. Then the graph of the function is given below. The domain of the function is a real number except 0 because the function is not ...The function f(g(x)) represents the amount that Sonia will earn per hour by baking bread. What is a Function? A function assigns the value of each element of one set to the other specific element of another set. Given f(x)=9x²+1 and g(x)=√(2x³). Therefore, the value of f(g(x)) will be, = 9(2x³) + 1 = 18x³ + 1Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might haveFor example, g(x) approaches 3 when x approaches 1, and f(3) = 10 but the function f(x) is discontinuous at f(3) such that the one side limits are different and hence its limit is undefined, will lim {x→1} f(g(x)) return the value 10?Set up the composite result function. g(f (x)) g ( f ( x)) Evaluate g(x− 2) g ( x - 2) by substituting in the value of f f into g g. g(x−2) = (x−2)+2 g ( x - 2) = ( x - 2) + 2. Combine the opposite terms in (x− 2)+2 ( x - 2) + 2. Tap for more steps... g(x−2) = x g ( x - 2) = x. Through a worked example involving f (x)=√ (x²-1) and g (x)=x/ (1+x), learn about function composition: the process of combining two functions to create a new function. This involves replacing the input of one function with the output of another function.Besides being called (composition) commutative, it is sometimes also said that such functions are permutable, e.g. see here.As an example, a classic result of Ritt shows that permutable polynomials are, up to a linear homeomorphism, either both powers of x, both iterates of the same polynomial, or both Chebychev polynomials.f(x)=2x+3, g(x)=-x^2+5, f(g(x)) en. Related Symbolab blog posts. Intermediate Math Solutions – Functions Calculator, Function Composition. Function composition is ...Chart drawing f (x),g (x) [1-5] /5. Disp-Num. [1] 2017/07/11 19:54 60 years old level or over / A teacher / A researcher / Useful /. Purpose of use. For 21 August 2017 Sun''s eclipse observations of General Relativity effects on directions of stars near the darkened Sun. Comment/Request..