How do you find the inverse of #2x+3=y#?

1 Answer
Jan 15, 2016

#f^-1(x) = 1/2 (x - 3 )#

Explanation:

To find the inverse of this function - change the subject to x.

2x + 3 = y

# rArr 2x = y - 3 rArr x = 1/2 (y - 3 ) #

The inverse is usually written in terms of x.

#rArr f^-1(x) = 1/2 (x - 3 ) #

As a check : if x = 2 then y = 2(2) + 3 = 4 + 3 =7

now if y = 7 : then x = #1/2 (7 - 3 ) = 1/2 xx 4 = 2#