1. The problem statement, all variables and given/known data Find the length of the curve traced by the given vector function on the indicated interval. r(t)=<t, tcost, tsint> ; 0<t<pi 2. Relevant equations s= ∫||r'(t)||dt 3. The attempt at a solution r'(t) = <1, -tsint + cost, tcost + sint> s= ∫||r'(t)||dt ||r'(t)|| = sqrt(1^2+(-tsint+cost)^2+(tcost+sint)^2) ||r'(t)|| = sqrt(1+t^2sin^2t-2tsintcost+cos^2t+t^2cos^t+2tsintcost+sin^2t) ||r'(t)|| = sqrt(1 + t^2sin^2t+t^2cos^2t+sin^2t+cos^2t) I'm not sure where to go from here. I was thinking of using the trig identity sin^2x+cos^2x= 1, but I don't think I can do that.