Question

sa se calculeze
${sin}^{2} 70 + {sin}^{2} 20$

Answer 1

$\sin^270^ {\circ} + \sin^2 20^{\circ} = \\ \\ = \sin^2(90-20)^{\circ} +\sin^2 2^{\circ} = \\ \\ = \cos^2 20^{\circ}+ \sin^2 20^{\circ} = \\ \\ = 1$