Find the exact length of the curve. Use a graph to determine the parameter interval.

r = cos^2 (theta/2)

The formula for the length of a polar curve is ∫ r2 + (dr/dθ) 2 from a to b.

In this case, dr/d θ is the derivative of the function r which is equal to - cos (theta/2) * sin (theta/2) which is equal to - 1/2 cos theta. Since there are no limits defined, we leave the formula as it is but one can use the calculator if there are limits present already