Let r(x) = f(g(h( where h(1) = 5, g(5) = 3, h'(1) = 4, g'(5) = 3, and f '(3) = 5. find r'(1).

======    to differentiate, we need to repeatedly use the chain rule.    the outside function is  ; the inside function is  .the chain rule says to differentiate the outside function and leave the inside function inside. then multiply that by the derivative of the inside function.    after that, repeat chain rule for  , using  as the outside function,  as inside.    since we are looking for r'(1):     we are given      we are given      we are given      again,     given      given