Question Number 69211 by Mikael last updated on 21/Sep/19 $${To}\:{conserve}\:{rice}\:{from}\:{a}\:{cooperative}\:{there}\:{is} \\ $$$${a}\:{foil}\:{of}\:{area}\:{A}=\mathrm{24}{cm}^{\mathrm{2}} .\:{The}\:{cooperatives} \\ $$$${want}\:{to}\:{build}\:{a}\:{barn}\:{in}\:{the}\:{shape}\:{of}\:{a}\:{parallelopiped} \\ $$$${square}\:{rectangle}\:{without}\:{cover}. \\ $$$${What}\:{should}\:{be}\:{the}\:{symmetrical}\:{dimensions}\:{for} \\ $$$${the}\:{volume}\:{to}\:{be}\:{maximum}? \\ $$ Terms of…
Question Number 134662 by mnjuly1970 last updated on 06/Mar/21 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:….{nice}\:\:{calculus}… \\ $$$$\:\:\:\:{prove}\:\:{that}:: \\ $$$$\:\:\:\boldsymbol{\phi}=\:\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\zeta\left(\mathrm{2}{n}\right)}{\left({n}+\mathrm{1}\right)\left(\mathrm{2}{n}+\mathrm{1}\right)}=\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\:\:\:\:\:\:\:\:\:…{m}.{n}… \\ $$ Answered by Dwaipayan Shikari last…
Question Number 69046 by Rio Michael last updated on 18/Sep/19 Commented by mathmax by abdo last updated on 18/Sep/19 $$\left.\mathrm{4}\right){we}\:{have}\:\:{y}={xarctanx}\:\Rightarrow{y}^{'} ={arctanx}\:+\frac{{x}}{\mathrm{1}+{x}^{\mathrm{2}} }\:\Rightarrow \\ $$$$\left({x}+{x}^{\mathrm{3}} \right){y}^{'}…
Question Number 3417 by RasheedSindhi last updated on 13/Dec/15 $${prove}\:{that}\:{among}\:{all}\:{closed}\:{figures} \\ $$$${having}\:{same}\:{perimeter}\:{circle} \\ $$$${has}\:{maximum}\:{area}. \\ $$ Commented by Filup last updated on 13/Dec/15 $$\mathrm{I}\:\mathrm{dont}\:\mathrm{understand}\:\mathrm{the}\:\mathrm{question} \\…
Question Number 134460 by bramlexs22 last updated on 04/Mar/21 $$ \\ $$2. When the cost of a bag of potatoes is $5 a supermarket sells…
Question Number 3370 by Filup last updated on 12/Dec/15 $${y}={ax}^{{n}} \\ $$$${y}+\delta{y}={a}\left({x}+\delta{x}\right)^{{n}} \\ $$$$\vdots \\ $$$$\frac{{dy}}{{dx}}={a}\underset{\delta{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\frac{\left({x}+\delta{x}\right)^{{n}} −{x}^{{n}} }{\delta{x}} \\ $$$$ \\ $$$$\mathrm{Show}\:\mathrm{that}\:\frac{{dy}}{{dx}}={anx}^{{n}−\mathrm{1}} \\ $$…
Question Number 134442 by mnjuly1970 last updated on 03/Mar/21 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:{nice}\:…..\:{calculus}… \\ $$$$\:\:\:\:{prove}\:{that}\::: \\ $$$$\:\:\:\:\:\:\:\:\:\boldsymbol{\phi}=\underset{{n}=\mathrm{1}} {\overset{\infty} {\prod}}\left(\mathrm{1}+\frac{\mathrm{1}}{{n}^{\mathrm{4}} }\right)=\frac{{cosh}\left(\mathrm{2}\pi\right)−{cos}\left(\mathrm{2}\pi\right)}{\mathrm{4}\pi^{\mathrm{2}} } \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:………………….. \\ $$ Answered by Dwaipayan…
Question Number 134432 by liberty last updated on 03/Mar/21 $$\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{maximum}\:\mathrm{and}\:\mathrm{minimum} \\ $$$$\mathrm{value}\:\mathrm{of}\:\mathrm{x}^{\mathrm{2}} +\mathrm{y}^{\mathrm{2}} +\mathrm{z}^{\mathrm{2}} \:\mathrm{subject}\:\mathrm{to}\: \\ $$$$\frac{\mathrm{x}^{\mathrm{2}} }{\mathrm{4}}+\frac{\mathrm{y}^{\mathrm{2}} }{\mathrm{5}}+\frac{\mathrm{z}^{\mathrm{2}} }{\mathrm{25}}\:=\:\mathrm{1}\:\mathrm{and}\:\mathrm{z}\:=\:\mathrm{x}+\mathrm{y}\:. \\ $$ Terms of Service…
Question Number 134435 by mnjuly1970 last updated on 03/Mar/21 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:….\mathscr{A}{dvanced}\:\:{calculus}…. \\ $$$$\:\:\:\:{prove}\:{that}:: \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{P}=\underset{{n}=\mathrm{1}} {\overset{\infty} {\prod}}\left(\mathrm{1}−\frac{\mathrm{1}}{{n}^{\mathrm{4}} }\right)=\frac{{sin}\left(\pi\right).{sinh}\left(\pi\right)}{\pi^{\:\mathrm{2}} }\:..\checkmark \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:………….\:……….. \\ $$ Answered by Dwaipayan…
Question Number 3330 by Filup last updated on 11/Dec/15 $$\mathrm{If}\:\mathrm{you}\:\mathrm{had}\:\mathrm{a}\:\mathrm{rectangle}\:\mathrm{with}\:\mathrm{side}\:\mathrm{lengths} \\ $$$${h}\:\mathrm{and}\:{b},\:\mathrm{the}\:\mathrm{area}\:\mathrm{is}\:\mathrm{given}\:\mathrm{by}: \\ $$$${A}\left({h},\:{b}\right)={hb} \\ $$$$ \\ $$$$\mathrm{If}\:\mathrm{I}\:\mathrm{were}\:\mathrm{to}\:\mathrm{change}\:\left(\mathrm{increase}\:\mathrm{or}\:\mathrm{decrease}\right) \\ $$$$\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{one}\:\mathrm{or}\:\mathrm{both}\:\mathrm{of}\:\mathrm{the}\:\mathrm{variables} \\ $$$$\mathrm{in}\:{A},\:\mathrm{how}\:\mathrm{can}\:\mathrm{I}\:\mathrm{write}\:\mathrm{the}\:\mathrm{change}\:\mathrm{in}\:\mathrm{area}? \\ $$ Answered…