∫cox2xdx (от π/12 до π/4)

[latex]int_{frac{pi}{12}}^{frac{pi}{4}}cos2x; dx=frac{1}{2}sin2x|_{frac{pi}{12}}^{frac{pi}{4}}=frac{1}{2}(sinfrac{pi}{2}-sinfrac{pi}{6})=frac{1}{2}(1-frac{1}{2})=frac{1}{4}[/latex]