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Category: Permutation and Combination

Calculer-lim-x-0-sin-x-2-n-1-2-n-sinx-cos-x-2-n-sin-2-x-2-n-

Question Number 195191 by Erico last updated on 26/Jul/23 $$\mathrm{Calculer}\underset{\mathrm{x}\rightarrow\mathrm{0}} {\:\mathrm{lim}}\frac{\mathrm{sin}\left(\frac{\mathrm{x}}{\mathrm{2}^{\mathrm{n}} }\right)−\frac{\mathrm{1}}{\mathrm{2}^{\mathrm{n}} }\mathrm{sinx}\:\mathrm{cos}\left(\frac{\mathrm{x}}{\mathrm{2}^{\mathrm{n}} }\right)}{\mathrm{sin}^{\mathrm{2}} \left(\frac{\mathrm{x}}{\mathrm{2}^{\mathrm{n}} }\right)} \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

Soit-x-gt-1-On-de-finie-la-suite-p-n-par-p-1-x-et-n-IN-p-n-1-2p-n-2-1-Montrer-que-lim-n-k-1-n-1-1-p-k-x-1-x-1-

Question Number 194960 by Erico last updated on 20/Jul/23 $$\mathrm{Soit}\:{x}>\mathrm{1}.\:\mathrm{On}\:\mathrm{d}\acute {\mathrm{e}finie}\:\mathrm{la}\:\mathrm{suite}\:\left(\mathrm{p}_{\mathrm{n}} \right)\:\mathrm{par}\: \\ $$$$\mathrm{p}_{\mathrm{1}} ={x}\:\:\mathrm{et}\:\forall\mathrm{n}\in\mathrm{IN}^{\ast} \:\:\:\:\:\mathrm{p}_{\mathrm{n}+\mathrm{1}} =\mathrm{2p}_{\mathrm{n}} ^{\mathrm{2}} −\mathrm{1} \\ $$$$\mathrm{Montrer}\:\mathrm{que}\:\underset{\mathrm{n}\rightarrow+\infty} {\mathrm{lim}}\:\underset{\mathrm{k}=\mathrm{1}} {\overset{\mathrm{n}} {\prod}}\left(\mathrm{1}+\frac{\mathrm{1}}{\mathrm{p}_{\mathrm{k}} }\right)=\sqrt{\frac{{x}+\mathrm{1}}{{x}−\mathrm{1}}}…

Prove-that-n-IN-k-1-2-n-1-1-sin-2-kpi-2-n-1-2-2n-1-2-3-Give-in-terms-of-n-k-1-2-n-1-1-sin-4-kpi-2-n-1-

Question Number 194638 by Erico last updated on 12/Jul/23 $$\mathrm{Prove}\:\mathrm{that}\:\forall{n}\in\mathrm{IN}^{\ast} \:\:\:\:\: \\ $$$$\:\:\:\underset{{k}=\mathrm{1}} {\overset{\mathrm{2}^{{n}} −\mathrm{1}} {\sum}}\:\frac{\mathrm{1}}{{sin}^{\mathrm{2}} \left(\frac{{k}\pi}{\mathrm{2}^{{n}+\mathrm{1}} }\right)}=\:\frac{\mathrm{2}^{\mathrm{2}{n}+\mathrm{1}} −\mathrm{2}}{\mathrm{3}} \\ $$$$\mathrm{Give}\:\mathrm{in}\:\mathrm{terms}\:\mathrm{of}\:{n}\:\:\:\underset{{k}=\mathrm{1}} {\overset{\mathrm{2}^{{n}} −\mathrm{1}} {\sum}}\:\frac{\mathrm{1}}{{sin}^{\mathrm{4}} \left(\frac{{k}\pi}{\mathrm{2}^{{n}+\mathrm{1}}…

If-log-a-y-1-3-and-log-8-a-x-1-then-show-that-y-2-x-1-

Question Number 193368 by MATHEMATICSAM last updated on 11/Jun/23 $$\mathrm{If}\:\mathrm{log}_{{a}} {y}\:=\:\frac{\mathrm{1}}{\mathrm{3}}\:\mathrm{and}\:\mathrm{log}_{\mathrm{8}} {a}\:=\:{x}\:+\:\mathrm{1}\:\mathrm{then}\:\mathrm{show} \\ $$$$\mathrm{that}\:{y}\:=\:\mathrm{2}^{{x}\:+\:\mathrm{1}} \\ $$ Answered by aba last updated on 11/Jun/23 $$\mathrm{log}_{\mathrm{8}} \mathrm{a}=\mathrm{x}+\mathrm{1}\:\Rightarrow\:\mathrm{ln}\left(\mathrm{a}\right)=\mathrm{3}\left(\mathrm{x}+\mathrm{1}\right)\mathrm{ln}\left(\mathrm{2}\right)\:\Rightarrow\:\mathrm{ln}\left(\mathrm{a}\right)=\mathrm{3ln}\left(\mathrm{2}^{\mathrm{x}+\mathrm{1}}…

There-are-20-persons-at-a-party-Maria-dansed-with-7-boys-Stacy-dansed-with-8-boys-Monia-dansed-with-9-boys-and-Eve-dansed-with-all-the-boys-at-the-party-How-many-girls-are-there-at-the-party-

Question Number 130899 by greg_ed last updated on 30/Jan/21 $$\mathrm{There}\:\mathrm{are}\:\mathrm{20}\:\mathrm{persons}\:\mathrm{at}\:\mathrm{a}\:\mathrm{party}. \\ $$$$\mathrm{Maria}\:\mathrm{dansed}\:\mathrm{with}\:\mathrm{7}\:\mathrm{boys}, \\ $$$$\mathrm{Stacy}\:\mathrm{dansed}\:\mathrm{with}\:\mathrm{8}\:\mathrm{boys}, \\ $$$$\mathrm{Monia}\:\mathrm{dansed}\:\mathrm{with}\:\mathrm{9}\:\mathrm{boys}\:\mathrm{and} \\ $$$$\mathrm{Eve}\:\mathrm{dansed}\:\mathrm{with}\:\mathrm{all}\:\mathrm{the}\:\mathrm{boys}\:\mathrm{at}\:\mathrm{the}\:\mathrm{party}. \\ $$$$\boldsymbol{\mathrm{How}}\:\boldsymbol{\mathrm{many}}\:\boldsymbol{\mathrm{girls}}\:\boldsymbol{\mathrm{are}}\:\boldsymbol{\mathrm{there}}\:\boldsymbol{\mathrm{at}}\:\boldsymbol{\mathrm{the}}\:\boldsymbol{\mathrm{party}}\:? \\ $$ Commented by mr…

Mr-Rahmat-decided-to-create-a-password-with-the-form-numbers-and-letterse-intermittntly-intermittent-can-also-be-letters-and-numbers-intermittently-but-no-nmbers-and-letters-are-the-same-It-c

Question Number 130689 by liberty last updated on 28/Jan/21 $$ \\ $$$$\mathrm{Mr}.\:\mathrm{Rahmat}\:\mathrm{decided}\:\mathrm{to}\:\mathrm{create}\:\mathrm{a}\:\mathrm{password}\: \\ $$$$\mathrm{with}\:\mathrm{the}\:\mathrm{form}\:\mathrm{numbers}\:\mathrm{and}\:\mathrm{letterse} \\ $$$$\mathrm{intermittntly}\:\:\mathrm{intermittent}\:\left(\:\mathrm{can}\:\mathrm{also}\:\mathrm{be}\right. \\ $$$$\left.\mathrm{letters}\:\mathrm{and}\:\mathrm{numbers}\:\mathrm{intermittently}\right)\:\mathrm{but}\:\mathrm{no} \\ $$$$\mathrm{nmbers}\:\mathrm{and}\:\mathrm{letters}\:\mathrm{are}\:\mathrm{the}\:\mathrm{same}.\:\mathrm{It}\: \\ $$$$\mathrm{chooses}\:\mathrm{to}\:\mathrm{use}\:\mathrm{numbers}\:\mathrm{on}\:\mathrm{the}\:\mathrm{set}\:\:\left\{\mathrm{2},\:\mathrm{5},\:\mathrm{8},\:\mathrm{9}\right\}\: \\ $$$$\mathrm{and}\:\mathrm{selects}\:\mathrm{the}\:\mathrm{letters}\:\mathrm{on}\:\mathrm{the}\:\mathrm{set}\:\left\{\:\mathrm{A},\:\mathrm{X},\:\mathrm{Y},\:\mathrm{W},\mathrm{Z}\right\}\: \\…

How-many-password-containing-6-characters-of-the-letters-in-the-word-Move-Now-

Question Number 130685 by EDWIN88 last updated on 28/Jan/21 $${How}\:{many}\:{password}\:{containing} \\ $$$$\mathrm{6}\:{characters}\:{of}\:{the}\:{letters}\:{in}\:{the}\: \\ $$$${word}\:''\:{Move}\:{Now}\:''\:? \\ $$ Answered by liberty last updated on 28/Jan/21 $$\mathrm{case}\left(\mathrm{1}\right)\:\underset{−} {\mathrm{O}}\underset{−}…