Find the magnitude and direction angle θ of the vector.

Question

u=4(cos102°i+sin102°j)

Answer 1

u=4(cos102°i+sin102°j)
= 4[cos102° , sin102°]

the direction angle is clearly 102°
magnitude = √(16(cos^2 102 + sin^2 102)
= √(16(1))
= 4