17. Sheryl is riding on a teeter-totter. Suppose 0 is the measure of the angle between the ground and Sheryl's highest point on the teeter-totter, and suppose the bar between Sheryl and the pivot has slope m - 2.8 when Sheryl is at the highest point. Which of the following statements is true? (a) tan(0) = 2.8 (b) tan(2.8) = 0 (c) sin(0) = -2.8 (d) cos(0) = -1 (e) cos(0) = 2.8