Question

If f(x) = 5x, what is f^-1(x)?

Answer 1

5x means 5 times x where x is some placeholder for a number. To get the inverse, we undo the multiplication. Division is the opposite of multiplication. So we'll divide both sides by 5 as one of the steps. Also, we'll swap x and y

y = 5x

x = 5y ... swap x and y

5y = x

5y/5 = x/5 .... divide both sides by 5

y = x/5

So this means the inverse function is equal to x/5

Answer 2

The answer will be fn-x