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Category: Relation and Functions

Trouver-toutes-les-fonctions-continues-f-R-R-verifiant-x-y-R-2-f-x-y-f-x-y-f-2-x-f-2-y-monsieur-j-ai-suppose-que-f-est-un-morphisme-mutiplicatif-de-R-mais-ca-ne-sort-pas-

Question Number 148558 by puissant last updated on 29/Jul/21 $$\mathrm{Trouver}\:\mathrm{toutes}\:\mathrm{les}\:\mathrm{fonctions}\:\mathrm{continues} \\ $$$$\mathrm{f}:\mathbb{R}\rightarrow\mathbb{R}\:\mathrm{verifiant}: \\ $$$$\forall\left(\mathrm{x},\mathrm{y}\right)\in\mathbb{R}^{\mathrm{2}} ,\:\mathrm{f}\left(\mathrm{x}+\mathrm{y}\right)\mathrm{f}\left(\mathrm{x}−\mathrm{y}\right)=\mathrm{f}^{\mathrm{2}} \left(\mathrm{x}\right)\mathrm{f}^{\mathrm{2}} \left(\mathrm{y}\right).. \\ $$$$\mathrm{monsieur}\:\mathrm{j}'\mathrm{ai}\:\mathrm{suppos}\acute {\mathrm{e}}\:\mathrm{que}\:\mathrm{f}\:\mathrm{est}\:\mathrm{un}\: \\ $$$$\mathrm{morphisme}\:\mathrm{mutiplicatif}\:\mathrm{de}\:\mathbb{R}..\:\mathrm{mais}\:\mathrm{ca}\:\mathrm{ne} \\ $$$$\mathrm{sort}\:\mathrm{pas}… \\…

let-U-n-z-C-z-n-1-simplify-p-0-2n-1-w-p-with-w-U-n-and-p-0-2n-1-2w-1-p-

Question Number 148501 by mathmax by abdo last updated on 28/Jul/21 $$\mathrm{let}\:\mathrm{U}_{\mathrm{n}} =\left\{\mathrm{z}\in\mathrm{C}\:/\mathrm{z}^{\mathrm{n}} \:=\mathrm{1}\right\}\:\:\mathrm{simplify} \\ $$$$\sum_{\mathrm{p}=\mathrm{0}} ^{\mathrm{2n}−\mathrm{1}} \:\mathrm{w}^{\mathrm{p}} \:\:\:\:\:\:\:\:\mathrm{with}\:\mathrm{w}\in\mathrm{U}_{\mathrm{n}} \:\:\: \\ $$$$\mathrm{and}\:\:\sum_{\mathrm{p}=\mathrm{0}} ^{\mathrm{2n}−\mathrm{1}} \left(\mathrm{2w}\:+\mathrm{1}\right)^{\mathrm{p}} \\…

let-and-roots-of-x-2-x-2-simplify-k-0-n-1-k-k-and-k-0-n-1-1-k-1-k-

Question Number 148502 by mathmax by abdo last updated on 28/Jul/21 $$\mathrm{let}\:\alpha\:\mathrm{and}\:\beta\:\mathrm{roots}\:\mathrm{of}\:\mathrm{x}^{\mathrm{2}} +\mathrm{x}+\mathrm{2} \\ $$$$\mathrm{simplify}\:\:\sum_{\mathrm{k}=\mathrm{0}} ^{\mathrm{n}−\mathrm{1}} \:\:\left(\alpha^{\mathrm{k}} \:+\beta^{\mathrm{k}} \right)\:\:\mathrm{and}\:\sum_{\mathrm{k}=\mathrm{0}} ^{\mathrm{n}−\mathrm{1}} \left(\:\frac{\mathrm{1}}{\alpha^{\mathrm{k}} }+\frac{\mathrm{1}}{\beta^{\mathrm{k}} }\right) \\ $$…

calculate-lim-x-0-ln-1-ln-1-x-x-

Question Number 82920 by abdomathmax last updated on 25/Feb/20 $${calculate}\:{lim}_{{x}\rightarrow\mathrm{0}} \frac{{ln}\left(\mathrm{1}+{ln}\left(\mathrm{1}+{x}\right)\right)}{{x}} \\ $$ Answered by mind is power last updated on 25/Feb/20 $${ln}\left(\mathrm{1}+{x}\right)\sim{x} \\ $$$$\Rightarrow{ln}\left(\mathrm{1}+{ln}\left(\mathrm{1}+{x}\right)\right)\sim{ln}\left(\mathrm{1}+{x}\right)…