For what values of x does the graph of f have a horizontal tangent? (Use n as your integer variable. Enter your answers as a comma-separated list.)

Question

For what values of x does the graph of f have a horizontal tangent? (Use n as your integer variable. Enter your answers as a comma-separated list.)
f(x) = x − 2 sin x

Steve · Accepted Answer

horizontal tangent means slope = 0 f'(x) = 1 - 2cosx 1-2cosx=0 cosx = 1/2 x = 2kpi +/- pi/3