Question

In the figure, a radar station detects an airplane approaching directly from the east. At first observation, the airplane is at distance d1 = 350 m from the station and at angle θ1 = 31° above the horizon. The airplane is tracked through an angular change Δθ = 123° in the vertical east–west plane; its distance is then d2 = 770 m. Find the (a) magnitude and (b) direction of the airplane's displacement during this period. Give the direction as an angle relative to due west, with a positive angle being above the horizon and a negative angle being below the horizon.

Answer 1

what's the trouble? Viewing from the side, the plane has moved from
(350 cos31°,350 sin31°) to (770 sin154°,770cos154°)
That is, from
(300,180) to (-692,338)

Now you can crank it out, right?