Question

Найдите sina, если cosa=3√11/10 и a Є‎ (0;0,5пи)

Answer 1

$Cos\alpha=\frac{3\sqrt{11}}{10} ;\alpha\in(0;0,5\pi)\\\\Sin\alpha =\sqrt{1-Cos^{2}\alpha}=\sqrt{1-(\frac{3\sqrt{11}}{10})^{2}}=\sqrt{1-\frac{99}{100}}=\sqrt{\frac{1}{100}}=\frac{1}{10}=0,1\\\\Otvet:\boxed{Sin\alpha=0,1}$