First we look for the angle of the vector, which will be given by: tan (x) = (- 2/3) Clearing x we have: x = ATAN (-2/3) = - 33.69 degrees. Which means that the angle is 33.69 degrees measured clockwise from the x axis. Equivalently the angle is 360-33.69 = 326.31 degrees 326.31 degrees measured counterclockwise from the x axis. The vector is then: v = 10 (cos (326.31) i + sin (326.31) j) answer v = 10 (cos (326.31) i + sin (326.31) j)