- [tex]sin^{2015}x + cos^{2015}x =1[/tex]
[tex]VT=sin^{2015}x+cos^{2015}x\leq sin^2x+cos^2x=1=VP[/tex]
Dấu = xảy ra khi [tex]\left\{\begin{matrix} sin^{2015}x=sin^2x\\ cos^{2015}x=cos^2x \end{matrix}\right.\Leftrightarrow x=k2\pi ,x=\frac{\pi }{2}+k2\pi[/tex]