30. A jogger travels a route that has two parts, the first is a displacement A of 2.50 km due south and the second involves a displacement B that points due east. (a) the resultant displacement of A + B has a magnitude of 3.75 km. what is the magnitude of B, and what is the direction of A + B relative to due south? (b) suppose that A - B had a magnitude of 3.75 km, what is the direction of A - B relative to due south?

First, have a sketch in front of you. Try to do it as accurate as possible. You'll obtain a right angled triangle. The hypotenuse is found to be the resultant displacement. With this drawing you should be able to solve (a). Find this first, then we'll continue.