Category: Algebra

Question Number 146277 by mathdanisur last updated on 12/Jul/21 $$\int cos\left(2x\right)dx=?$$ Answered by physicstutes last updated on 12/Jul/21 $$\mathrm{Nice}\mathrm{question}.\mathrm{lol}$$$$\int \cos \left(2x\right)dx=\frac{\sin 2x}{2}+k$$$$\int\mathrm{cos}\:\left({ax}\right){dx}\:=\:\frac{\mathrm{sin}\:{ax}}{{a}}+{k} \…

Question Number 146272 by mathdanisur last updated on 12/Jul/21 $${log}_{\mathit{x}}(x^2+1)⩽1$$ Commented by iloveisrael last updated on 13/Jul/21 $$\:\mathrm{log}\:_{\mathrm{x}} \left(\mathrm{x}^{\mathrm{2}} +\mathrm{1}\right)\leqslant\mathrm{log}\:_{\mathrm{x}} \left(\mathrm{x}\right)…

Question Number 146261 by mathdanisur last updated on 12/Jul/21 $$4cos\left(50°\right)-\frac{1}{sin\left(20°\right)}=?$$ Answered by bemath last updated on 12/Jul/21 $$\frac{4\cos 50°.\cos 70°-1}{\sin 20°}=$$$$\frac{2(\cos 120°+\cos 20°)-1}{\sin 20°}=$$$$\:\frac{−\mathrm{1}+\mathrm{2cos}\:\mathrm{20}°−\mathrm{1}}{\mathrm{sin}\:\mathrm{20}°}\:=\: \…

Question Number 146244 by mathdanisur last updated on 12/Jul/21 $${(\sqrt{5}-2)}^{\frac{2x^2-1}{2}}={(\sqrt{5}+2)}^{\frac{3x-7}{4}}\Rightarrow x=?$$ Answered by gsk2684 last updated on 12/Jul/21 $$use\sqrt{5}-2=\frac{1}{\sqrt{5}+2}$$$${compare}\:{exponents}…

Question Number 80706 by TawaTawa last updated on 05/Feb/20 Answered by mind is power last updated on 05/Feb/20 $$weusesinrelation\Rightarrow$$$$\frac{BD}{sin\left(\frac{A}{2}\right)}=\frac{AB}{sin\left(\mathrm{\angle }BDA\right)}$$$$\frac{CD}{sin\left(\frac{A}{2}\right)}=\frac{AD}{sin(180-\mathrm{\angle }BDA)}=\frac{AC}{sin\left(\mathrm{\angle }BDA\right)}$$$$\Rightarrow\frac{{BD}}{{CD}}=\frac{{AB}}{{AC}}=\frac{{c}}{{b}}…