Question

sin4x*tg2x+2cos^2 2x

Answer 1

$\sin 4x \cdot \text{tg} \ 2x + 2\cos^{2} 2x = 2\sin2x \cos 2x \cdot \dfrac{\sin 2x}{\cos 2x} + 2\cos^{2} 2x = \\= 2\sin^{2} 2x + 2\cos^{2} 2x = 2(\sin^{2} 2x + \cos^{2} 2x) = 2 \cdot 1 = 2$