Question Number 207374 by sniper237 last updated on 13/May/24 $${Show}\:{that}\:\:\underset{{k}=\mathrm{0}} {\overset{{n}} {\sum}}\left({C}_{{n}} ^{{k}} \right)^{\mathrm{2}} ={C}_{\mathrm{2}{n}} ^{{n}} \\ $$ Answered by mr W last updated on…
Question Number 207407 by hardmath last updated on 13/May/24 Commented by Frix last updated on 13/May/24 $$\mathrm{2}.\:…=\mathrm{2}\sqrt{\mathrm{3}}\mathrm{cos}\:\mathrm{10}° \\ $$ Commented by Frix last updated on…
Question Number 207402 by MATHEMATICSAM last updated on 13/May/24 $${f}\left({x}\right)\:+\:\mathrm{2}{f}\left(\frac{\mathrm{1}}{{x}}\right)\:=\:\mathrm{3}{x}. \\ $$$$\:{f}\:'\left({x}\right)\:=\:? \\ $$ Answered by Frix last updated on 13/May/24 $${x}={t}:\:{f}\left({t}\right)+\mathrm{2}{f}\left(\frac{\mathrm{1}}{{t}}\right)=\mathrm{3}{t} \\ $$$${x}=\frac{\mathrm{1}}{{t}}:\:{f}\left(\frac{\mathrm{1}}{{t}}\right)+\mathrm{2}{f}\left({t}\right)=\frac{\mathrm{3}}{{t}} \\…
Question Number 207394 by hardmath last updated on 13/May/24 $$\frac{\mathrm{a}}{\mathrm{b}}\:\:=\:\:\frac{\mathrm{c}}{\mathrm{d}} \\ $$$$\mathrm{a}^{\mathrm{3}} \:−\:\mathrm{b}^{\mathrm{3}} \:=\:\mathrm{625} \\ $$$$\mathrm{c}^{\mathrm{3}} \:−\:\mathrm{d}^{\mathrm{3}} \:=\:\mathrm{1} \\ $$$$\mathrm{Find}:\:\:\:\mathrm{a},\mathrm{b},\mathrm{c},\mathrm{d}\:=\:? \\ $$ Answered by mr…
Question Number 207395 by hardmath last updated on 13/May/24 $$\mathrm{Geometric}\:\mathrm{series}: \\ $$$$\frac{\mathrm{b}_{\mathrm{4}} \:\centerdot\:\mathrm{b}_{\mathrm{7}} \:\centerdot\:\mathrm{b}_{\mathrm{10}} }{\mathrm{b}_{\mathrm{1}} \:\centerdot\:\mathrm{b}_{\mathrm{3}} \:\centerdot\:\mathrm{b}_{\mathrm{5}} }\:\:=\:\:\mathrm{2}^{\mathrm{12}} \:\:\:\:\:\mathrm{find}:\:\:\:\frac{\mathrm{b}_{\mathrm{5}} }{\mathrm{b}_{\mathrm{2}} }\:\:=\:\:? \\ $$ Answered by…
Question Number 207372 by sniper237 last updated on 12/May/24 $$\mathrm{2}\:{students}\:{are}\:{passing}\: \\ $$$${a}\:{test}\:{of}\:\:{n}\:{questions}\:{with} \\ $$$${the}\:{same}\:{chance}\:{to}\:{find}\:{each}\:{one} \\ $$$${Show}\:\:{the}\:{chance}\:{that}\:{they}\:{both} \\ $$$$\:{don}'{t}\:{find}\:{a}\:{same}\:{question}\:{is}\:\:\left(\frac{\mathrm{3}}{\mathrm{4}}\right)^{{n}} \\ $$ Commented by A5T last updated…
Question Number 207341 by mr W last updated on 12/May/24 Answered by som(math1967) last updated on 12/May/24 Commented by som(math1967) last updated on 12/May/24 $${ar}\:{of}\:\bigtriangleup{BOC}…
Question Number 207359 by Shrodinger last updated on 12/May/24 $$\int\frac{{ln}\left({x}^{\mathrm{2}} +{sin}\left({sin}\left({e}^{{x}} \right)\right)\right)}{\:\sqrt{{x}+{tan}\left({ln}\left({x}\right)\right)}}{dx} \\ $$ Answered by Berbere last updated on 12/May/24 $${it}\:{semms}\:{non}\:{close}\:{forme}\: \\ $$ Commented…
Question Number 207352 by NasaSara last updated on 12/May/24 $${calculate}: \\ $$$$\:\int_{\frac{\Pi}{\mathrm{4}}} ^{\frac{\Pi}{\mathrm{2}}} \lfloor{cot}\left({x}\right)\rfloor\:{dx} \\ $$ Commented by NasaSara last updated on 12/May/24 $${thank}\:{you} \\…
Question Number 207354 by NasaSara last updated on 12/May/24 Commented by mr W last updated on 12/May/24 $${there}\:{are}\:{integrals}\:{like}\:{following} \\ $$$$\int\int…\int\int{f}\left({x}_{\mathrm{1}} ,{x}_{\mathrm{2}} ,…,{x}_{{n}} \right){dx}_{\mathrm{1}} {dx}_{\mathrm{2}} …{dx}_{{n}}…