Các dạng bài tập tự luyện về cos^3x? cos^3x

If ∫sinxsin3x+cos3xdx=αloge|1+tanx|+βloge|1−tanx+tan2x|+γtan−1(2tanx−1√3)+C, where C is constant of integration, then the value of 18(α+β+γ2) is · | · | · | · | ... If x is an acute angle and sin ( x + 28 ° ) = cos ( 3 x − 78 ° ) then the angle is · The equation b cos ⁡ x 2 cos 2 x − 1 = b + sin ⁡ x cos 2 ⁡ x − 3 sin ⁡ x ... Apr 21, 2017 ... cos(3x) in terms of cos(x), write cos(3x) in terms of cos(x), using the angle sum formula and the double angle formulas, ... Solution. Observe that $2\cos 4x\cos x = \cos 5x + \cos 3x$ by the sum-to-product formulas. Defining $a = \cos 3x$ and $b = \cos 5x$ , we have $a^3 + b^3 ... esin 3x cos 3x dx = 1. 3 esin 3x + C. 53. Z e7x e7x + 5 dx = 1. 7 ln(e7x + 5) + C. 54. Z tan x dx = Z sin x cos x dx. Using the substitution u = cos x, we see ... sa sinu du= -cosu+ (= - cos/√x) + C. U=3x du=3dx. 4S JX. U=√x dur 24/7 dx. 5. S cos(3x) dx. { sinu +(= {} sn13x |. 6. $ et dz. S =}{} cosu dy = = sinu + C =. Jul 1, 2019 ... Proof Tan 3x is = Sin 3x/ Cos 3x using De Moivre's theorem · updatesvc · Steven G · Dr.Peterson · updatesvc · Steven G · updatesvc. New member. Yp = -9 A Cos 3x-9B Sin 3x. Plug into ODE: (-9A (os 3x-98 Sin 3x)+4(-3A Sin 3x + 3B Cos3x). + 4 CA Cos 3x + B Sin 3x). = [-5A ]. T-5. +12B Cos 3x + -12A-5B ... Apr 24, 2017 ... A more-general version of this question: "How can we sum up sin and cos series when the angles are in arithmetic progression?" Feb 28, 2013 ... 3 Answers 3 ... You have cosxcosy=12(cos(x+y)+cos(x−y)). Hence cos(2x)cos(3x)=12(cos(5x)+cosx). This should be straightforward to integrate. ... Or ...