Let A, B, and C Be Three Points on the Unit

Essay

Let A, B, and C be three points on the unit sphere centered at the origin whose spherical coordinates are A = (1, 0, 0), B = $\left( 1,0 , \frac { \pi } { 4 } \right)$ , and C = $\left( 1 , \frac { \pi } { 2 } , \frac { \pi } { 3 } \right)$ .(a) Find the angle between $\overrightarrow { O A }$ and $\overrightarrow { O B }$ .(b) Find the angle between $\overrightarrow { O A }$ and $\overrightarrow { O C }$ .(c) Find the angle between $\overrightarrow { O B }$ and $\overrightarrow { O C }$ .