Find the first 4 times when a robotic arm is at h=0
Hi I need help with this simple question that I just can't seem to wrap my head around.
The arm of a robot moves up and down such that the height h at time t is given by h=sin^2 t - 0.2 sin t. Find the first 4 times when the arm is at h = 0.
The answer is t=0, 0.201, 2.94, and pi. But how do we arrive to these 4 numbers?