Question

cos²x-sin²x=0
√3sin 5x+cos 5x=0

Answer 1

cos²x-sin²x=0
cos2x=0
2x=π/2+πn, n ∈ z
x=π/4+πn/2, n ∈ Z

√3sin5x+cos5x=0|:cos5x
√3tg5x+1=0
tg5x=-1/√3
5x=π/6+πn, n ∈ Z
x=π/30+πn/5, n ∈ Z