1. ## inverse functions

hi im stuck on a question:
a) draw the graph of y=3x and its inverse function
b) write down the equation of the line that y=3x and its inverse are symmetrical about.
ive done a but im stuck on b can someone please explain b to me?
thankyou

2. The graphs of $f$ and $f^{-1}$ are symmetrical about the first bisector of the axes, which has the equation $y=x$

3. ## oh........

thanks so much!!!!