Question Number 18077 by virus last updated on 15/Jul/17 $${A}\:{mango}\:{in}\:{a}\:{tree}\:{is}\:{located}\:\left(\mathrm{30},\mathrm{40}\right)\:{from}\:{the} \\ $$$${point}\:{of}\:{projection}\:{of}\:{stone}.{Find}\:{the}\: \\ $$$${minimum}\:{speed}\:{and}\:{the}\:{angle}\:{of}\:{projevtion} \\ $$$${of}\:{the}\:{stone}\:{so}\:{as}\:{to}\:{hit}\:{the}\:{mango} \\ $$ Answered by ajfour last updated on 15/Jul/17…
Question Number 83606 by MJS last updated on 04/Mar/20 $$\mathrm{a}\:\mathrm{car}\:\mathrm{drives}\:\mathrm{at}\:\mathrm{a}\:\mathrm{speed}\:\mathrm{of}\:\mathrm{120}\:\mathrm{km}/\mathrm{hr} \\ $$$$\mathrm{it}\:\mathrm{starts}\:\mathrm{to}\:\mathrm{brake}\:\mathrm{at}\:\mathrm{a}\:\mathrm{road}\:\mathrm{mark}\:{A}\:\mathrm{and} \\ $$$$\mathrm{passes}\:\mathrm{a}\:\mathrm{road}\:\mathrm{mark}\:{B}\:\mathrm{at}\:\mathrm{a}\:\mathrm{speed}\:\mathrm{of} \\ $$$$\mathrm{60}\:\mathrm{km}/\mathrm{hr}.\:\mathrm{acceleration}\:\mathrm{is}\:\mathrm{constant}.\:\mathrm{the} \\ $$$$\mathrm{distance}\:{AB}\:\mathrm{is}\:\mathrm{4}\:\mathrm{km}. \\ $$$$\left(\mathrm{1}\right)\:\mathrm{calculate}\:\mathrm{the}\:\mathrm{acceleration} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{calculate}\:\mathrm{the}\:\mathrm{time}\:\mathrm{between}\:{A}\:\mathrm{and}\:{B} \\ $$$$\left(\mathrm{3}\right)\:\mathrm{there}\:\mathrm{are}\:{n}\:\mathrm{reflector}\:\mathrm{posts}\:\mathrm{between}\:{A} \\…
Question Number 149121 by mathdanisur last updated on 03/Aug/21 $$\frac{\mathrm{2}\centerdot\left({cos}\mathrm{85}°\:+\:\boldsymbol{{i}}{sin}\mathrm{85}°\right)}{\:\sqrt{\mathrm{2}}\centerdot\left({cos}\mathrm{40}°\:+\:\boldsymbol{{i}}{sin}\mathrm{40}°\right)}\:=\:? \\ $$ Answered by bramlexs22 last updated on 03/Aug/21 $$\left.\sqrt{\mathrm{2}}\:\mathrm{e}^{\mathrm{i}\left(\mathrm{85}°−\mathrm{40}°\right.} \right)=\sqrt{\mathrm{2}}\:\mathrm{e}^{\mathrm{i45}°} =\sqrt{\mathrm{2}}\left(\frac{\sqrt{\mathrm{2}}}{\mathrm{2}}+\frac{\sqrt{\mathrm{2}}}{\mathrm{2}}{i}\right) \\ $$$$\:\:\:=\mathrm{1}+{i} \\…
Question Number 18046 by virus last updated on 14/Jul/17 Answered by mrW1 last updated on 14/Jul/17 $$\mathrm{t}_{\mathrm{P}−\mathrm{D}} =\mathrm{10}/\mathrm{2}=\mathrm{5}\:\mathrm{s} \\ $$$$\mathrm{t}_{\mathrm{P}−\mathrm{B}} =\mathrm{6}/\mathrm{2}=\mathrm{3}\:\mathrm{s} \\ $$$$\mathrm{h}=\mathrm{h}_{\mathrm{P}−\mathrm{D}} −\mathrm{h}_{\mathrm{P}−\mathrm{N}} =\frac{\mathrm{1}}{\mathrm{2}}\mathrm{g}\left(\mathrm{5}^{\mathrm{2}}…
Question Number 18015 by alex041103 last updated on 13/Jul/17 $${Just}\:{for}\:{fun} \\ $$$${Prove}\:{that}\:{there}\:{are}\:{no}\:{real}\:{numbers}\:{A}\:{and}\:{B}\:{that} \\ $$$${satisfy}\: \\ $$$${sinA}=\frac{\mathrm{2}}{{sinB}} \\ $$ Commented by alex041103 last updated on 13/Jul/17…
Question Number 17991 by alex041103 last updated on 13/Jul/17 $${Evaluate}\:\sqrt{\mathrm{1}+\mathrm{2}\sqrt{\mathrm{1}+\mathrm{3}\sqrt{\mathrm{1}+\mathrm{4}\sqrt{\mathrm{1}+…}}}} \\ $$ Commented by alex041103 last updated on 13/Jul/17 $${just}\:{for}\:{fun} \\ $$$${whoever}\:{wants}\:{can}\:{try}\:{to}\:{generalize} \\ $$$$\sqrt{{A}+{B}_{\mathrm{1}} \sqrt{{A}+{B}_{\mathrm{2}}…
Question Number 17989 by alex041103 last updated on 13/Jul/17 $${Solve}\:{for}\:{x} \\ $$$${x}^{{x}^{{x}^{{x}^{….} } } } =\:\mathrm{4} \\ $$ Commented by alex041103 last updated on 13/Jul/17…
Question Number 83524 by liki last updated on 03/Mar/20 Commented by liki last updated on 03/Mar/20 $$…{help}\:{me}\:{plz}\:{qns}\:{no}.\:\mathrm{5},\mathrm{7}\:{and}\:\mathrm{9} \\ $$ Commented by liki last updated on…
Question Number 83481 by gny last updated on 02/Mar/20 Commented by gny last updated on 02/Mar/20 $${sir}\:{could}\:{you}\:{help}\:{me}\:\:\:\:\:\:\:\:\:\:\:{Find}\:\:\alpha+\beta \\ $$ Commented by mathmax by abdo last…
Question Number 17936 by Rishabh#1 last updated on 12/Jul/17 $$\mathrm{Two}\:\mathrm{particles}\:\mathrm{start}\:\mathrm{moving}\:\mathrm{towards} \\ $$$$\mathrm{each}\:\mathrm{other}\:\mathrm{with}\:\mathrm{constant}\:\mathrm{acceleration} \\ $$$$\mathrm{of}\:\:\mathrm{1}\:{m}/{s}^{\mathrm{2}} .\:\mathrm{If}\:\mathrm{their}\:\mathrm{initial}\:\mathrm{separation}\:\mathrm{is} \\ $$$$\mathrm{100}\:\mathrm{m},\:\mathrm{find}\:\mathrm{after}\:\mathrm{what}\:\mathrm{time}\:\mathrm{they}\:\mathrm{will} \\ $$$$\mathrm{meet}\:\mathrm{each}\:\mathrm{other} \\ $$$$\left(\mathrm{A}\right)\:\mathrm{40}{s}\:\:\:\:\left(\mathrm{B}\right)\:\mathrm{45}{s}\:\:\:\:\left(\mathrm{C}\right)\:\mathrm{50}\:{s}\:\left(\mathrm{D}\right)\mathrm{55}{s} \\ $$ Commented by…