How do you find the inverse of #f(x) =1/4x+7#?

1 Answer
Jun 19, 2015

Write #y = 1/4x+7#

then rearrange to find #x = 4(y-7)#, so the inverse function is:

#f^-1(y) = 4(y-7)#

Explanation:

Let #y = f(x) = 1/4x+7#

Subtract #7# from both ends to get:

#y-7 = 1/4x#

Multiply both sides by #4# to get:

#x = 4(y-7)#

This defines #x# in terms of #y# in such a way that the equation #y = 1/4x+7# is satisfied, so it defines the inverse function:

#f^-1(y) = 4(y-7)#