Question

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

Answer 1

`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`