Question) The polar curve C is given by the polar equation r=1+cos(theta)

Find the length of C.

Answer) This is what I have so far:

r = 1 + cos(theta)

Since L = INT(sqrt[1 + (dr/d(theta))^2])d(theta)

Therefore,

L = int(sqrt[1+sin^2(theta)])d(theta) (with integral from 0 to 2)

then Im stuck... please help to solve this!!

zee