Question

найдите сtgA если sinA=0,8​

Answer 1

$\cos\alpha=\pm\sqrt{1-\sin^2\alpha}=\pm\sqrt{1-0,64}=\pm\sqrt{0,36}=\pm0,6\\\\ctg\alpha=\frac{\cos\alpha}{\sin\alpha}=\frac{\pm0,6}{0,8}=\pm\frac34$