Find sinθ between two vectors v = (4, -3) and u = (3, 2)

Answer 1

u•v = (4)(3) + (-3)(2) = 6
now recall that
u•v = |u| |v| cosθ so that means
5*√13 cosθ = 6
cosθ = 6/(5√13)
Draw the triangle, and you can see that
sinθ = 17/(5√13)