Category: Relation and Functions

Question Number 11172 by agni5 last updated on 15/Mar/17 $$\mathrm{Tangent}\mathrm{to}\mathrm{the}\mathrm{curve}{(\mathrm{x}+\mathrm{y})}^3={(\mathrm{x}-\mathrm{y}+2)}^2$$$$\mathrm{at}(-1,1).$$ Answered by ajfour last updated on 15/Mar/17 $$y=x+2$$…

Question Number 11166 by chux last updated on 14/Mar/17 Commented by ridwan balatif last updated on 15/Mar/17 $$\cos 4\theta =\cos (2\theta +2\theta )$$$$={2\cos }^{2}2\theta -1$$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\mathrm{2}\left\{\mathrm{cos}\left(\theta+\theta\right)\right\}^{\mathrm{2}} −\mathrm{1} \…

Question Number 142228 by mathmax by abdo last updated on 28/May/21 $$\mathrm{developpf}\left(\mathrm{x}\right)=\frac{2}{3+\mathrm{cosx}}\mathrm{at}\mathrm{fourier}\mathrm{serie}$$ Answered by mathmax by abdo last updated on 28/May/21 $$\mathrm{another}\:\mathrm{way}\:\mathrm{f}\:\mathrm{is}\:\mathrm{even}\:\Rightarrow\mathrm{f}\left(\mathrm{x}\right)=\frac{\mathrm{a}_{\mathrm{o}} }{\mathrm{2}}\:+\sum_{\mathrm{n}=\mathrm{1}}…

Question Number 76657 by Tony Lin last updated on 29/Dec/19 $$provethat{sin}^{-1}\left(tanhx\right)={tan}^{-1}\left(sinhx\right)$$ Answered by john santu last updated on 29/Dec/19 $$\left(\mathrm{1}\right)\:\mathrm{tan}\:{hx}\:=\:\mathrm{sin}\:{y} \…

Question Number 11067 by suci last updated on 10/Mar/17 $$ifE=\{f\mid f:\mathbb{R}\to \mathbb{R}continuousfunctionwithf\left(x\right)\in \mathbb{Q},\mathrm{\forall }x\in \mathbb{R}\},$$$$thenE=\dots .???$$ Commented by FilupS last updated on 10/Mar/17 $$\mathbb{Q}=\mathrm{irrational}\mathrm{numbers}\mathrm{set}$$$$ \…