An elastic band is hung on a hook and a mass is hung on the lower end of the band. When the mass is pulled downward and then released, it vibrates vertically. The equation of motion is
s = 3 cos t + 9 sin t, t â‰¥ 0,
s is measured in centimeters and
t in seconds. (Take the positive direction to be downward.)
(a) Find the velocity and acceleration at time t.
Simplify the trigonometric expression.