The Length of the Curve $x ( t ) = 1 - \cos t , y ( t ) = 1 + \sin t$

Multiple Choice

The length of the curve $x ( t ) = 1 - \cos t , y ( t ) = 1 + \sin t$ with $t \in \left[ - \frac { \pi } { 2 } , \frac { \pi } { 2 } \right]$ is

A) $\frac { \pi } { 2 }$
B) $\pi$
C) $\frac { 3 \pi } { 8 }$
D) $\frac { 3 \pi } { 4 }$
E) $2 \pi$