Find the Distance Traveled by a Particle Moving on the Curve

Essay

Find the distance traveled by a particle moving on the curve given by $\vec { r } ( t ) = \left\langle \sin \left( \frac { \pi } { 2 } t \right) , \cos \left( \frac { \pi } { 2 } t \right) , t \right\rangle$ as $t$ goes from $t = - 1$ to $t = 1$