Calculus
posted by Elyse .
Three forces with magnitudes 75 pound, 100 lb, and 125 pound act on an object at angles of 30 degrees, 45 degrees, and 120 degrees respectively. Find the direction and magnitude of the resultant vector.

convert each to (x,y) coordinates
add them up
convert result back to speed and direction
75 @ 30° = (64.95,37.50)
...