Write the values of x in[0,π]for which sin 2x,12 and cos 2x are in A.P.
We want to find the value of x for which 12−sin 2x=cos 2x−12⇒cos 2x+sin 2x=1⇒1−2 sin2x+2 sin x cos x=1⇒2 sin x(cos x−sin x)=0⇒sin x=0 or cos x =sin x⇒x=0,π4,π