Raymond B. answered • 03/20/21
Tutor
5
(2)
Math, microeconomics or criminal justice
f(x) = y = 2x +9, to find the inverse function, switch x and y and solve for y
x = 2y + 9
2y = x-9
y = (x-9)/2 = x/2 - 9/2
f^-1(x) = x/2 - 9/2
Just to check, let x = 2, then f(x) = 2(2)+9 = 13
f^-1(x) = 13/2 - 9/2 = 4/2 = 2. You started with 2 and ended with 2, the inverse of a function leads you back to where you started.
Graph them, f(x) and its inverse are symmetric about y=x.
they have an inverse slope 2 and 1/2. the x intercept for f(x) = -4 1/2 which is the y intercept for the inverse function. 9 is the y intercept for f(x) and 9 is the x intercept for the inverse function.
