What is this and what do you put in

How do you find the circumfrance of a circle?

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1

If you double the input of a function and it results in half the output, and if you triple the input and it results in a third of the output, what can be guessed about the function? check all that apply.