$pt<=>(1+sin2x)(sinx+cosx)=sinx+cosx+2cosx$$<=>(1+sin2x-1)(sinx+cosx)=2cosx$$<=>2sinx.cosx(sinx+cosx)=2cosx$$<=>cosx(sin^2x+sinx.cosx-1)=0$$<=>cosx(cos^2x+sinx.cosx)=0$$<=>cos^2x(sinx+cosx)=0$$<=>\sqrt2cos^2x.sin(x+\frac{\pi}4)=0$$XONG$
$pt<=>(1+sin2x)(sinx+cosx)=sinx+cosx+2cosx$$<=>(1+sin2x-1)(sinx+cosx)=2cosx$$<=>2sinx.cosx(sinx+cosx)=2cosx$$<=>cosx(sin^2x+sinx.cosx-1)=0$$<=>cosx(cos^2x+sinx.cosx)=0$$<=>cos^2x(sinx+cosx)=0$$<=>\sqrt2cos^2xsin(x+\frac{\pi}4)=0$$XONG$
$pt<=>(1+sin2x)(sinx+cosx)=sinx+cosx+2cosx$$<=>(1+sin2x-1)(sinx+cosx)=2cosx$$<=>2sinx.cosx(sinx+cosx)=2cosx$$<=>cosx(sin^2x+sinx.cosx-1)=0$$<=>cosx(cos^2x+sinx.cosx)=0$$<=>cos^2x(sinx+cosx)=0$$<=>\sqrt2cos^2x
.sin(x+\frac{\pi}4)=0$$XONG$