√2cosx-1=0 решите срочно

Question

√2cosx-1=0 решите срочно

Answer 1

√2 Cos x = 1
Cosx = 1/√2
x = +-arcCos1/√2 + 2πk, k ∈Z
x = +-π/4 + 2πk , k ∈ Z