Question

Найдите корень уравнения: 10cos^2 x+3cosx + 1 = 0

Answer 1

$10cos^2x+3cosx+1=0\\\\t=cosx\; ,\; \; 10t^2+3t+1=0\\\\D=9-40=-31\ \textless \ 0\; \; \Rightarrow \quad net\; reshenij$

Answer 2

Решение тригонометрии