t Find the arc length parameter along the given curve from the point where t= O by evaluating the integral s(t) = I|v(-r)| d1. Then find the length of the indicated portion of the curve r(t) = 6cost 0 fl: i+Gsintj+6t k, whereOStsZ. The arc length parameter along the curve, starting at t= 0 is s(t) = (Type an exact answer, using radicals as needed.)