Question

Find the angle between two vectors. In radians and in degrees.

u=<1,0,-3>, v=<2,-2,1>

I got

radians = 1.676

degrees = 96
Steve
u•v = |u|*|v|*cosθ
-1 = √10*√5 cosθ
θ = 81.9°

check your math (and mine!)