Question

Anyone know how to solve inverse of functions ? plz help

Answer 1

In each let y = f(x) and rearrange making x the subject

(7)

y = 3x + 9 ( subtract 9 from both sides )

3x = y - 9 ( divide both sides by 3 )

x =
`(y-9)/(3)`

change y back into terms of x

`f^(-1)`(x) =
`(x-9)/(3)`

(8)

y = 5x - 2

5x = y + 2 ( divide both sides by 5 )

x =
`(y+2)/(5)`

`f^(-1)`(x) =
`(x+2)/(5)`

(9)

y = - x + 2

x = 2 - y

`f^(-1)`(x) = 2 - x

(10)

y = - 4x + 3

4x = 3 - y ( divide both sides by 4 )

x =
`(3-y)/(4)`

`f^(-1)`(x) =
`(3-x)/(4)`

(11)

y = 0.5x - 2

0.5x = y + 2 ( divide both sides by 0.5 )

x = 2(y + 2)

`f^(-1)`(x) = 2x + 4

(12)

y = - 0.25x + 6

0.25x = 6 - y ( divide both sides by 0.25 )

x = 4(6 - y )

`f^(-1)`(x) = 24 - 4x