math
posted by Gary on .
Please help me. I can't seem to get the answer of 165 degrees.
Find the angle ϴ between the vectors.
u=3i3j, v=2i+2√3j

The magnitude of u is sqrt 18.
The magnitude of v is 4
The dot product of u and v is
u*v = 6 6sqrt3
= 6(1+sqrt3)
The cosine of the angle between the vectors is
(u*v)/uv