Find 5π27π233cos(3x)dx\displaystyle {\int_{{\frac{{-{5}\pi}}{{2}}}}^{{\frac{{{7}\pi}}{{2}}}}}{33}{\cos{{\left({3}{x}\right)}}}{\left.{d}{x}\right.}

5π27π233cos(3x)dx=\displaystyle {\int_{{\frac{{-{5}\pi}}{{2}}}}^{{\frac{{{7}\pi}}{{2}}}}}{33}{\cos{{\left({3}{x}\right)}}}{\left.{d}{x}\right.}=