Question

найдите tg a, если cos a=-1/√2 и а є (0,5π; π)

Answer 1

$sin alpha = - frac{1}{2} \ cos alpha = sqrt{1 - { (frac{ - 1}{2}) }^{2} } = \ sqrt{ frac{3}{4} } = - frac{ sqrt{3} }{2} \ tg alpha = - frac{1}{2} div ( - frac{ sqrt{3} }{2} ) = frac{1}{ sqrt{3} } = frac{ sqrt{3} }{3}$