Remember that the unit-vector form is a vector equation that relates a vector to its x, y, and z components:
Anytime we're asked to relate the magnitude and direction of a three-dimensional vector to its components, there are four basic equations we might use:
Let V = 20.5 i + 22.5 j − 13.5 k.
(a) Find the magnitude of V.
(b) What angle does this vector make with the x-, y-, and z-axes?