# How do you find all points on the graph of f(x)=sin^2x at which the tangent line is horizontal?

kpi/2 \ \ \ ;\ \ \ kinZZ
${f}^{'} \left(x\right) = 2 \sin x \cos x = \sin 2 x$
$\sin \left(2 x\right) = 0 \setminus \setminus \setminus$ when \ \ \ \2x=kpi\ \ \ ; \ \ \ k in ZZ