Question

Решите уравнение
cos² (π-x) + 8cos (π-x) + 7 = 0

Answer 1

cos^2(П-х)+8cos(П-х)+7=0
(-cos(x))^2+8x(-cos(x))+0
(-cos(x))^2-8cos(x)
cos(x)^2-8cos(x)