McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
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Exercise 9 Page 225

To algebraically determine the inverse of the given relation, we need to exchange x and y and solve for y.

Inverse: f^(- 1)(x)=4x+12
Graph:

Practice makes perfect
Before we can find the inverse of the given function, we need to replace f(x) with y. f(x)=1/4x-3 ⇔ y=1/4x-3 To algebraically determine the inverse of the given relation, we exchange x and y and solve for y. ccc Given Equation & & Inverse Equation [0.8em] y=1/4 x-3 & & x=1/4 y-3The result of isolating y in the new equation will be the inverse of the given function.
x=1/4y-3
Solve for y
x+3=1/4y
4x+12=y
y=4x+12
Now we have the inverse of the given function. Lastly, we need to replace y with f^(- 1)(x). y=4x+12 ⇔ f^(- 1)(x)=4x+12

Graphing the Function

Because the given function is in slope-intercept form, we can graph it using its slope and y-intercept. It has a slope of 14 and a y-intercept at (0,- 3).

Graphing the Inverse of the Function

Because the inverse function is in slope-intercept form, we can graph it using its slope and y-intercept. It has a slope of 4 and a y-intercept at (0,12).

Let's add it to the graph of the given function so that we can more easily see how it is a reflection across the y=x.