Question

Вопрос №77042

Answer 1

sinx+cosx=0

sinx=-cosx

cos(pi/2 - x + 2n pi)=cos(pi+x)

pi/2 - x + 2n pi = pi+x

x=-pi/4 + n pi

 interval [0;2pi]  n=1, i  2

x=(3/4)pi   i   x=(7/4)pi