Hi all, Im having trouble with this question:

A chain hangs so that its shape is of the form y=56ch(x/56).

Determine correct to 4 SF

a) the value of y when x is 35

I simply plugged this into the calculator and got the answer 67.29

and

b) the value of x when y is 65.

Im not sure how i rearrange the equation or what to do really at all.

Thanks, Dan