y = cos ( x ) y = sin ( 2 x ) x = 0 x = π 2 {\displaystyle {\begin{aligned}&\color {red}\mathbf {y=\cos(x)} &\color {royalblue}\mathbf {y=\sin(2x)} \\&x=0&x={\frac {\pi }{2}}\\\end{aligned}}}
cos ( x ) = sin ( 2 x ) x = π 2 x = π 6 {\displaystyle {\begin{aligned}\cos(x)&=\sin(2x)\\x&={\frac {\pi }{2}}\\x&={\frac {\pi }{6}}\\\end{aligned}}}
∫ 0 π 6 ( cos ( x ) − sin ( 2 x ) ) d x + ∫ π 6 π 2 ( sin ( 2 x ) − cos ( x ) ) d x {\displaystyle \int _{0}^{\frac {\pi }{6}}\left(\cos(x)-\sin(2x)\right)dx+\int _{\frac {\pi }{6}}^{\frac {\pi }{2}}\left(\sin(2x)-\cos(x)\right)dx}
