Given g(x) = x sin(x) 2VT find the line tangent to g(x) at E = 1. If f(x) = 23 cos(x) find, f'(x) and f"(x). Find the values of x for which f(x) = ex cos(x) has a horizontal tangent line. Find the 38-th derivative of sin(x) without actually taking 38 derivatives. Hint: Find the first four derivatives of sin(x)... notice a pattern