Question

What is the inverse funtion of y=7^x?

Answer 1

`f^(-1)(x)=log_7(x)`

Explanation:

Switch `x` and `y` and then solve for `y`:

`x= 7^y`

Use logarithm:
One way:
`logx=log(7^y)`
`logx= ylog7`
`y= logx/log7`

Or:
Knowing that:
`b^y=x` then `log_b(x)=y`

So:
`log_7(x)=y`