Question Number 22487 by ajfour last updated on 19/Oct/17 Commented by ajfour last updated on 19/Oct/17 $${Q}.\:\mathrm{22473}\:\left({solution}\:\right) \\ $$ Answered by ajfour last updated on…
Question Number 88021 by naka3546 last updated on 07/Apr/20 Commented by MJS last updated on 07/Apr/20 $$\mathrm{I}\:\mathrm{get}\:\mathrm{4}\vee\mathrm{5}…\:\mathrm{not}\:\mathrm{sure}\:\mathrm{how}\:\mathrm{I}\:\mathrm{got}\:\mathrm{there}… \\ $$ Commented by naka3546 last updated on…
Question Number 153553 by mnjuly1970 last updated on 08/Sep/21 $$ \\ $$$$\:{sin}\left(\mathrm{9}\right)\:+\:{sin}\left(\mathrm{21}\right)+{sin}\left(\mathrm{39}\right)\overset{?} {=}\frac{\varphi}{\:\sqrt{\mathrm{2}}} \\ $$$$\:\:\:\varphi:=\:{golden}\:{ratio} \\ $$$$\:{m}.{n} \\ $$ Answered by bramlexs22 last updated on…
Question Number 22483 by Tinkutara last updated on 19/Oct/17 $$\mathrm{Predict}\:\mathrm{the}\:\mathrm{density}\:\mathrm{of}\:\mathrm{Cs}\:\mathrm{from}\:\mathrm{the} \\ $$$$\mathrm{density}\:\mathrm{of}\:\mathrm{the}\:\mathrm{following}\:\mathrm{elements} \\ $$$$\mathrm{K}\:\mathrm{0}.\mathrm{86}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \:\:\:\:\:\:\:\:\mathrm{Ca}\:\mathrm{1}.\mathrm{548}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \\ $$$$\mathrm{Sc}\:\mathrm{2}.\mathrm{991}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \:\:\:\:\:\mathrm{Rb}\:\mathrm{1}.\mathrm{532}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \\ $$$$\mathrm{Sr}\:\mathrm{2}.\mathrm{68}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \:\:\:\:\:\:\:\:\mathrm{Y}\:\mathrm{4}.\mathrm{34}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \\ $$$$\mathrm{Cs}\:?\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{Ba}\:\mathrm{3}.\mathrm{51}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{La}\:\mathrm{6}.\mathrm{16}\:\mathrm{g}/\mathrm{cm}^{\mathrm{3}}…
Question Number 153555 by mnjuly1970 last updated on 08/Sep/21 $$ \\ $$$$\:\:\:\:\:\Omega\::=\:\int_{\mathrm{0}} ^{\:\frac{\pi}{\mathrm{2}}} {cos}\left(\mathrm{2}{x}\right).{ln}\left({sin}\left({x}\right)\right){dx}\overset{?} {=}\:−\frac{\pi}{\mathrm{4}} \\ $$$$\:\:\:\:\:\:\:\:\:\:{solution}\:\left(\mathrm{1}\:\right) \\ $$$$\:\:\:\:\:\Omega\::=\:\int_{\mathrm{0}} ^{\:\frac{\pi}{\mathrm{2}}} \left(\:\mathrm{2}{cos}^{\:\mathrm{2}} \left({x}\right)−\mathrm{1}\right){ln}\left({sin}\left({x}\right)\right){dx} \\ $$$$\:\:\:\:\:\::=\:\mathrm{2}\int_{\mathrm{0}} ^{\:\frac{\pi}{\mathrm{2}}}…
Question Number 22481 by ajfour last updated on 19/Oct/17 Commented by ajfour last updated on 19/Oct/17 $${Q}.\:\mathrm{22479}\:\left({Solution}\right) \\ $$ Answered by ajfour last updated on…
Question Number 88014 by ajfour last updated on 07/Apr/20 $${If}\:{there}\:{is}\:{no}\:{second}'{s}\:{hand}\:{on} \\ $$$${a}\:{clock}\:{and}\:{the}\:{minute}\:{and}\:{hour} \\ $$$${hand}\:{move}\:{in}\:{continuous}\:{fashion}, \\ $$$${then}\:{exactly}\:{at}\:{what}\:{time}\:{between} \\ $$$$\mathrm{02}:\mathrm{10}\:\:{and}\:\mathrm{02}:\mathrm{15}\:{does}\:{the}\:{position} \\ $$$${of}\:{the}\:{two}\:{hands}\:{exactly}\:{coincide}? \\ $$ Answered by mr…
Question Number 22479 by Tinkutara last updated on 19/Oct/17 $$\mathrm{A}\:\mathrm{ladder}\:\mathrm{of}\:\mathrm{mass}\:{m}\:\mathrm{is}\:\mathrm{leaning}\:\mathrm{against}\:\mathrm{a} \\ $$$$\mathrm{wall}.\:\mathrm{It}\:\mathrm{is}\:\mathrm{in}\:\mathrm{static}\:\mathrm{equilibrium}\:\mathrm{making} \\ $$$$\mathrm{an}\:\mathrm{angle}\:\theta\:\mathrm{with}\:\mathrm{the}\:\mathrm{horizontal}\:\mathrm{floor}. \\ $$$$\mathrm{The}\:\mathrm{coefficient}\:\mathrm{of}\:\mathrm{friction}\:\mathrm{between}\:\mathrm{the} \\ $$$$\mathrm{wall}\:\mathrm{and}\:\mathrm{the}\:\mathrm{ladder}\:\mathrm{is}\:\mu_{\mathrm{1}} \:\mathrm{and}\:\mathrm{that} \\ $$$$\mathrm{between}\:\mathrm{the}\:\mathrm{floor}\:\mathrm{and}\:\mathrm{the}\:\mathrm{ladder}\:\mathrm{is}\:\mu_{\mathrm{2}} . \\ $$$$\mathrm{The}\:\mathrm{normal}\:\mathrm{reaction}\:\mathrm{of}\:\mathrm{the}\:\mathrm{wall}\:\mathrm{on}\:\mathrm{the} \\…
Question Number 88015 by M±th+et£s last updated on 07/Apr/20 $${if}\:{u}={f}\left({x},{y}\right)\:{where}\:{x}={rcos}\left(\theta\right)\:\:,\:{y}={r}\:{sin}\left(\theta\right) \\ $$$${prove}\: \\ $$$$\left(\frac{\partial{u}}{\partial{x}}\right)^{\mathrm{2}} +\left(\frac{\partial{u}}{\partial{y}}\right)^{\mathrm{2}} =\left(\frac{\partial{u}}{\partial{r}}\right)^{\mathrm{2}} +\frac{\mathrm{1}}{{r}}\left(\frac{\partial{u}}{\partial\theta}\right)^{\mathrm{2}} \\ $$ Terms of Service Privacy Policy Contact:…
Question Number 22478 by 123 45 polytechnicien last updated on 19/Oct/17 $$\begin{cases}{{x}+{y}^{\mathrm{2}} +{z}^{\mathrm{3}} =\mathrm{3}}\\{{y}+{z}^{\mathrm{2}} +{x}^{\mathrm{3}} =\mathrm{3}}\\{{z}+{x}^{\mathrm{2}} +{z}^{\mathrm{3}} =\mathrm{3}}\end{cases} \\ $$$${trouver}\:{les}\:{solutions}\:{positives} \\ $$$$ \\ $$ Commented…