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Author: Tinku Tara

2-1-x-2-1-x-4-

Question Number 71089 by 20190927 last updated on 11/Oct/19 $$\left(\sqrt{\sqrt{\mathrm{2}}−\mathrm{1}}\right)^{\mathrm{x}} +\left(\sqrt{\sqrt{\mathrm{2}}+\mathrm{1}}\right)^{\mathrm{x}} =\mathrm{4} \\ $$ Answered by Henri Boucatchou last updated on 11/Oct/19 $$\:\sqrt{\mathrm{2}}\:+\:\mathrm{1}\:=\:\frac{\mathrm{1}}{\:\sqrt{\mathrm{2}}\:−\:\mathrm{1}},\:\boldsymbol{{let}}\:\:\boldsymbol{{a}}\:=\:\sqrt{\sqrt{\mathrm{2}}−\mathrm{1}} \\ $$$$\:\left(\sqrt{\sqrt{\mathrm{2}}\:−\mathrm{1}}\right)^{\boldsymbol{{x}}}…

I-have-two-circles-side-by-side-Circle-1-has-radius-r-Circle-2-has-radius-1-3-r-If-I-roll-circle-2-around-circle-1-until-it-reaches-the-begining-how-many-times-will-it-roll-

Question Number 5546 by FilupSmith last updated on 19/May/16 $$\mathrm{I}\:\mathrm{have}\:\mathrm{two}\:\mathrm{circles}\:\mathrm{side}\:\mathrm{by}\:\mathrm{side}. \\ $$$$\mathrm{Circle}\:\mathrm{1}\:\mathrm{has}\:\mathrm{radius}\:{r}. \\ $$$$\mathrm{Circle}\:\mathrm{2}\:\mathrm{has}\:\mathrm{radius}\:\frac{\mathrm{1}}{\mathrm{3}}{r}. \\ $$$$ \\ $$$$\mathrm{If}\:\mathrm{I}\:\mathrm{roll}\:\mathrm{circle}\:\mathrm{2}\:\mathrm{around}\:\mathrm{circle}\:\mathrm{1}\:\mathrm{until} \\ $$$$\mathrm{it}\:\mathrm{reaches}\:\mathrm{the}\:\mathrm{begining}, \\ $$$$\mathrm{how}\:\mathrm{many}\:\mathrm{times}\:\mathrm{will}\:\mathrm{it}\:\mathrm{roll}? \\ $$ Commented…

What-plane-geometrical-figures-could-be-produced-by-joining-vertices-of-a-cube-for-example-square-What-largest-area-2-dimensional-can-be-obtained-by-joining-vertices-of-a-cube-when-its-side-is

Question Number 5543 by Rasheed Soomro last updated on 19/May/16 $$\bullet\mathrm{What}\:\boldsymbol{\mathrm{plane}}\:\boldsymbol{\mathrm{geometrical}}\:\boldsymbol{\mathrm{figures}} \\ $$$$\mathrm{could}\:\mathrm{be}\:\mathrm{produced}\:\mathrm{by}\:\mathrm{joining} \\ $$$$\boldsymbol{\mathrm{vertices}}\:\boldsymbol{\mathrm{of}}\:\boldsymbol{\mathrm{a}}\:\boldsymbol{\mathrm{cube}}? \\ $$$$\left(\mathrm{for}\:\mathrm{example}\::\:\mathrm{square}\right) \\ $$$$\bullet\mathrm{What}\:\mathrm{largest}\:\mathrm{area}\left(\mathrm{2}\:\mathrm{dimensional}\right)\:\mathrm{can}\:\mathrm{be}\:\mathrm{obtained} \\ $$$$\mathrm{by}\:\mathrm{joining}\:\mathrm{vertices}\:\mathrm{of}\:\mathrm{a}\:\mathrm{cube}\:\mathrm{when}\:\mathrm{its}\:\mathrm{side}\:\mathrm{is}\:\mathrm{x}? \\ $$ Terms of…

The-surface-area-of-a-cylinder-is-A-2pir-2-2pirh-As-h-0-the-shape-becomes-a-2D-circle-so-should-lim-h-0-A-pir-2-Or-is-it-that-as-h-0-it-creates-a-circle-of-3-dimensions-with-infinte

Question Number 5542 by FilupSmith last updated on 19/May/16 $$\mathrm{The}\:\mathrm{surface}\:\mathrm{area}\:\mathrm{of}\:\mathrm{a}\:\mathrm{cylinder}\:\mathrm{is}: \\ $$$${A}=\mathrm{2}\pi{r}^{\mathrm{2}} +\mathrm{2}\pi{rh} \\ $$$$ \\ $$$$\mathrm{As}\:{h}\rightarrow\mathrm{0},\:\mathrm{the}\:\mathrm{shape}\:\mathrm{becomes}\:\mathrm{a}\:\mathrm{2D}\:\mathrm{circle}, \\ $$$$\mathrm{so}\:\mathrm{should}\:\:\:\:\:\underset{{h}\rightarrow\mathrm{0}} {\mathrm{lim}}\:{A}\:=\:\pi{r}^{\mathrm{2}} \:\:\:??? \\ $$$$\mathrm{Or}\:\mathrm{is}\:\mathrm{it}\:\mathrm{that}\:\mathrm{as}\:{h}\rightarrow\mathrm{0},\:\mathrm{it}\:\mathrm{creates}\:\mathrm{a}\:\mathrm{circle} \\ $$$$\mathrm{of}\:\mathrm{3}\:\mathrm{dimensions}\:\mathrm{with}\:\mathrm{infintesimally}\:\mathrm{small}…

If-a-1-a-23-then-a-1-4-1-a-1-4-

Question Number 136614 by bemath last updated on 24/Mar/21 $${If}\:{a}+\frac{\mathrm{1}}{{a}}\:=\:\mathrm{23}\:{then}\:\sqrt[{\mathrm{4}}]{{a}}\:+\:\frac{\mathrm{1}}{\:\sqrt[{\mathrm{4}}]{{a}}}\:=? \\ $$ Answered by mr W last updated on 24/Mar/21 $${a}+\frac{\mathrm{1}}{{a}}=\left(\sqrt{{a}}+\frac{\mathrm{1}}{\:\sqrt{{a}}}\right)^{\mathrm{2}} −\mathrm{2}=\mathrm{23} \\ $$$$\sqrt{{a}}+\frac{\mathrm{1}}{\:\sqrt{{a}}}=\mathrm{5} \\…

How-many-planes-can-pass-through-vertices-of-a-cube-a-when-each-plane-contains-at-least-three-vertices-b-when-each-plane-contains-exactly-four-vertices-c-Could-we-say-that-a-plane-can-pass-at-mo

Question Number 5539 by Rasheed Soomro last updated on 19/May/16 $$\mathrm{How}\:\mathrm{many}\:\boldsymbol{\mathrm{planes}}\:\mathrm{can}\:\mathrm{pass}\:\mathrm{through} \\ $$$$\boldsymbol{\mathrm{vertices}}\:\mathrm{of}\:\mathrm{a}\:\boldsymbol{\mathrm{cube}}, \\ $$$$\left.{a}\right)\:\mathrm{when}\:\mathrm{each}\:\mathrm{plane}\:\mathrm{contains}\:\boldsymbol{\mathrm{at}}\:\boldsymbol{\mathrm{least}} \\ $$$$\boldsymbol{\mathrm{three}}\:\boldsymbol{\mathrm{vertices}}. \\ $$$$\left.{b}\right)\:\mathrm{when}\:\mathrm{each}\:\mathrm{plane}\:\mathrm{contains}\:\boldsymbol{\mathrm{exactly}} \\ $$$$\boldsymbol{\mathrm{four}}\:\boldsymbol{\mathrm{vertices}}. \\ $$$$\left.{c}\right)\:\mathrm{Could}\:\mathrm{we}\:\mathrm{say}\:\mathrm{that}\:\mathrm{a}\:\mathrm{plane}\:\mathrm{can}\:\mathrm{pass} \\ $$$$\boldsymbol{\mathrm{at}}\:\boldsymbol{\mathrm{most}}\:\boldsymbol{\mathrm{four}}\:\boldsymbol{\mathrm{vertices}}?…

Question-71073

Question Number 71073 by TawaTawa last updated on 11/Oct/19 Commented by Prithwish sen last updated on 11/Oct/19 $$\mathrm{a}^{\mathrm{2}} =\:\mathrm{b}^{\mathrm{2}} +\mathrm{c}^{\mathrm{2}} +\mathrm{2bc} \\ $$$$\therefore\:\boldsymbol{\mathrm{bc}}\:=\:\frac{\boldsymbol{\mathrm{a}}^{\mathrm{2}} −\boldsymbol{\mathrm{b}}^{\mathrm{2}} −\boldsymbol{\mathrm{c}}^{\mathrm{2}}…