Category: Arithmetic

Question Number 47413 by Tawa1 last updated on 09/Nov/18 $$\mathrm{Calculate}:{1999}^2-{1998}^2+{1997}^2-{1996}^2\dots -2^2+1^2$$ Answered by mr W last updated on 09/Nov/18…

Question Number 112810 by Aina Samuel Temidayo last updated on 09/Sep/20 Answered by Rasheed.Sindhi last updated on 10/Sep/20 $$t_1,t_2,t_3,\dots ,t_n;n\in \mathbb{E}\dots \dots \dots \dots \left(1\right)$$$${Sum}\:{of}\:{odd}\:{numbered}\:{terms}:…

Question Number 47111 by peter frank last updated on 04/Nov/18 Commented by MrW3 last updated on 04/Nov/18 $$\frac{4!/2!}{7!/3!/2!}=\frac{4!3!}{7!}=\frac{3\times 2\times 1}{7\times 6\times 5}=\frac{1}{35}$$ Commented by peter frank last…

Question Number 46860 by 786786AM last updated on 01/Nov/18 $$\mathrm{Find}\mathrm{the}\mathrm{sum}\mathrm{to}\mathrm{infinity}\mathrm{whose}{\mathrm{n}}^{\mathrm{th}}\mathrm{term}\mathrm{is}\frac{\mathrm{n}}{2^{\mathrm{n}-1}}.$$ Commented by maxmathsup by imad last updated on 01/Nov/18 $${let}\:{s}\left({x}\right)=\sum_{{n}=\mathrm{1}} ^{\infty}…

Question Number 46829 by peter frank last updated on 01/Nov/18 Answered by tanmay.chaudhury50@gmail.com last updated on 01/Nov/18 $$eqnoffocalchordis$$$${y}={tan}\theta\left({x}−\sqrt{{a}^{\mathrm{2}} −{b}^{\mathrm{2}} }\:\right)\:{focaus}\left(\sqrt{{a}^{\mathrm{2}} −{b}^{\mathrm{2}} }\:,\mathrm{0}\right) \…