Помогите решить Cos14x+sin7x-1=0

[latex]cos14x+sin7x-1=0 \\ cos^{2}7x-sin^{2}7x+sin7x-1=0 \\ -sin^{2}7x+sin7x-(1-cos^{2}7x)=0 \\ -sin^{2}7x+sin7x-sin^{2}7x)=0 \\ 2sin^{2}7x-sin7x=0 \\ sin7x*(2sin7x-1)=0 \\ [/latex] 1) [latex]sin7x=0 \\ 7x=0+ \pi *n \\ x= \frac{ \pi *n}{7} [/latex] 2) [latex]2sin7x-1=0 \\ sin7x= \frac{1}{2}\\ 7x=(-1)^{n}* \frac{ \pi }{6} + \pi *n \\ x=(-1)^{n}* \frac{ \pi }{42} + \frac{ \pi*n }{7}\\ [/latex]