Find the exact solutions of the equation in the interval [0,2pi) enter your answers as a comma separated list Sin 2x + sin x =0 Solution sin2x + sinx =0 use the trig identity : sin2x = 2sinxcosx 2sinxcosx +sinx =0 sinx( 2cosx+1) =0 sinx =0 x= 0, pi in the interval [0,2pi ) cosx = -1/2 x= pi -pi/3 , pi +pi/3 (cos is -ve in IInd and IIIrd quadrant) x = 2pi/3, 4pi/3.