Question

Find the angle between two vectors, 6 and 8 units long, when their resultant is (a) 10units long and (b) 4units long.

Answer 1

Think of 2 separate triangles


For part (a) we are lucky because the angle between the two vectors is 90 degrees, this is because if we use Pythagoras Theorem 6^2 + 8^2 = 10^2


Just working on part (b) now...