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Category: Integration

cos-7x-cos-8x-1-2cos-5x-dx-

Question Number 136992 by liberty last updated on 28/Mar/21 =cos7xcos8x1+2cos5xdx=? Answered by EDWIN88 last updated on 28/Mar/21 =cos7xcos8x1+2cos5xdxSimplifytheintegrandbyEulersformula$$\frac{\mathrm{cos}\:\mathrm{7x}−\mathrm{cos}\:\mathrm{8x}}{\mathrm{1}+\mathrm{2cos}\:\mathrm{5x}}\:=\:\frac{\mathrm{e}^{\mathrm{i7x}} +\mathrm{e}^{−\mathrm{i7x}}…