Question

Use the Racetrack Principle and the fact that sin 0 = 0

Answer 1

Oh maybe that since the derivative of sine is cosine and cosine is bounded above by 1, then sin⁡(x)−sin⁡(0) /x−0≤1
\frac{\sin(x)-\sin(0)}{x-0}\leq 1 so sin⁡(x)≤x