Question

If f(x) = 5x + 3, then what is f-1(x)

Answer 1

f(x) = 5x + 3


y = 5x + 3


x = 5y + 3


Now solve for y

Answer 2

I dont understand

Answer 3

What do you get when you solve for y

Answer 4

I started off by replacing f(x) with y. Then I swapped x and y. The goal now is to solve for y.

Answer 5

plug in what you got for x

Answer 6

what do you mean

Answer 7

plug in what I got for x into the y= equation

Answer 8

no, just tell me what you get when you solve for y

Answer 9

5

Answer 10

solve

x = 5y + 3

for y

Answer 11

y = 3/-5

Answer 12

\[\Large x = 5y + 3\]

\[\Large x-3 = 5y\]

\[\Large \frac{x-3}{5} = y\]

\[\Large y=\frac{x-3}{5} \]

So the inverse function is

\[\Large f^{-1}(x)=\frac{x-3}{5} \]

Answer 13

thank you but where did the f^-1 come from

Answer 14

that stands for the inverse function

Answer 15

once you've solved for y, that's effectively finding the inverse

Answer 16

ok. Thanks for the help

Answer 17

np