Hello, can you please help me with this exercise? Thank you.

If g : [a, b] R is differentiable with piecewise continuity, we define the length of the graph of g on [a, b] to be the length of the path t (t, g(t)) for t [a, b]. (a) Prove that the length of the graph of g at [a, b] is.

ab1+g)(t)dt

b) Find the length of the graph of y = log(x) at x=1 and x=2.