sinx=+-1 => x=\frac{ \pi }{2}+ \pi n;" alt="1)sin ^{2} x=1 => sinx=+-1 => x=\frac{ \pi }{2}+ \pi n;" align="absmiddle" class="latex-formula">
cosx=+-1 => x=\pi n;" alt="2) cos^{2}x=1 => cosx=+-1 => x=\pi n;" align="absmiddle" class="latex-formula">
tgx=+-1 => x=\frac{ \pi }{4}+ \frac{ \pi }{2} n;" alt="3) tg^{2}x=1 => tgx=+-1 => x=\frac{ \pi }{4}+ \frac{ \pi }{2} n;" align="absmiddle" class="latex-formula">