Question

I don't understand how to find the inverese of a one to one function.

Find the inverese of the one to one function.

9. f(x)=-4x+7
Is the inverese suppose to be
f^-1(x)=x-7/-4?

12. f(x)= square root of x-8
I don't understand how to find the inverese on this one.

16. f(x)= 4/(5x-1)
I don't understand how to find the inverese on this one.

Answer 1

9. The inverse function gives you x back if the dependent variable is f(x). Call f(x) "y"

y = -4x + 7
x = (1/4) (7-y)
Now you can switch y and x, since it is a "dummy" variable anyway.

f^-1 (x) = (7-x)/4

12. y = (sqrt x) - 8
y+8 = sqrt x
(y+8)^2 = x
f^-1 (x) = (x+8)^2