Question

Найти синус, и котангенс угла, если Cos a = 0.6

Answer 1

$cos alpha ^{2} +sin alpha ^{2} =1 \ sin alpha = sqrt{1-cos alpha^{2} } = sqrt{1-0.36} =0.8 \ ctg alpha = frac{cos alpha }{sin alpha } = frac{0.6}{0.8} =0.75$