Find the error(s) in the following "Proof", and, as usual, provide an explanation. Statement The function | COS(x)| is constant on the interval [0, 7:]. Proof Let F(x) = | cos(x)|. Note that %Cos(x) = sin(x) and sin(x) > 0 if 0 0 it follows that dF d cos(x) = 1=sinx