Find the Angle Between the Vectors U and V $\mathbf { u } = \cos \left( \frac { \pi } { 3 } \right) \mathbf { i } + \sin \left( \frac { \pi } { 3 } \right) \mathbf { j }$

Multiple Choice

Find the angle between the vectors u and v. $\mathbf { u } = \cos \left( \frac { \pi } { 3 } \right) \mathbf { i } + \sin \left( \frac { \pi } { 3 } \right) \mathbf { j }$ , $v = \cos \left( \frac { 3 \pi } { 4 } \right) i + \sin \left( \frac { 3 \pi } { 4 } \right) j$ ​

A) $40 ^ { \circ }$
B) $15 ^ { \circ }$
C) $75 ^ { \circ }$
D) $105 ^ { \circ }$
E) $70 ^ { \circ }$