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Category: Algebra

if-cos-a-find-5-6cos2-cos4-

Question Number 148445 by mathdanisur last updated on 28/Jul/21 $${if}\:\:\:{cos}\boldsymbol{\alpha}\:=\:\sqrt{\boldsymbol{{a}}} \\ $$$${find}\:\:\:\mathrm{5}\:-\:\mathrm{6}{cos}\mathrm{2}\boldsymbol{\alpha}\:+\:{cos}\mathrm{4}\boldsymbol{\alpha}\:=\:? \\ $$ Commented by mathdanisur last updated on 28/Jul/21 $${Thank}\:{you}\:{Ser} \\ $$$${But},\:=\sqrt{\boldsymbol{\alpha}}\:\left({alfa}\:{no}\right)\:\:=\sqrt{\boldsymbol{{a}}} \\…

Question-82897

Question Number 82897 by aseer imad last updated on 25/Feb/20 Commented by mr W last updated on 25/Feb/20 $${certainly}! \\ $$$$\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}{f}\left({x}\right)={f}\left(\mathrm{0}\right)=\mathrm{0}+\mathrm{1}+\mathrm{2}=\mathrm{3} \\ $$$$\underset{{x}\rightarrow\mathrm{1}} {\mathrm{lim}}{f}\left({x}\right)={f}\left(\mathrm{1}\right)=\mathrm{1}+\mathrm{0}+\mathrm{1}=\mathrm{2}…

lim-x-x-cos-2x-3x-1-

Question Number 148416 by mathdanisur last updated on 27/Jul/21 $$\underset{\boldsymbol{{x}}\rightarrow\infty} {{lim}}\frac{{x}!\:-\:{cos}\left(\mathrm{2}{x}\right)}{\mathrm{3}{x}\:+\:\mathrm{1}}\:=\:? \\ $$ Answered by mathmax by abdo last updated on 28/Jul/21 $$\mathrm{we}\:\mathrm{have}\:\frac{\mathrm{x}!−\mathrm{cos}\left(\mathrm{2x}\right)}{\mathrm{3x}+\mathrm{1}}=\frac{\mathrm{x}!}{\mathrm{3x}+\mathrm{1}}−\frac{\mathrm{cos}\left(\mathrm{2x}\right)}{\mathrm{3x}+\mathrm{1}} \\ $$$$\mathrm{lim}_{\mathrm{x}\rightarrow+\infty}…

Question-82873

Question Number 82873 by mr W last updated on 25/Feb/20 Commented by mr W last updated on 25/Feb/20 $${A}\:{rope}\:{with}\:{length}\:\boldsymbol{{l}}\:{and}\:{mass}\:\boldsymbol{{m}}\:{is} \\ $$$${fixed}\:{at}\:{one}\:{end}\:{on}\:{the}\:{top}\:{of}\:{a}\:{roller} \\ $$$${with}\:{diameter}\:{h}\:{as}\:{shown}.\:{Find}\:{the} \\ $$$${maximal}\:{possible}\:{horizontal}\:{distance}…

x-x-64-x-

Question Number 148395 by mathdanisur last updated on 27/Jul/21 $$\boldsymbol{{x}}^{\boldsymbol{{x}}} \:=\:\mathrm{64} \\ $$$$\Rightarrow\:\boldsymbol{{x}}\:=\:? \\ $$ Answered by Math_Freak last updated on 27/Jul/21 $${if}\:{x}>\mathrm{0} \\ $$$${xlnx}\:=\:{ln}\mathrm{64}…

cos40-1-2cos80-

Question Number 148388 by mathdanisur last updated on 27/Jul/21 $${cos}\mathrm{40}°\left(\mathrm{1}\:-\:\mathrm{2}{cos}\mathrm{80}°\right)\:=\:? \\ $$ Answered by liberty last updated on 27/Jul/21 $$\mathrm{cos}\:\mathrm{40}°\left(\mathrm{1}−\mathrm{2}\left(\mathrm{2cos}\:^{\mathrm{2}} \mathrm{40}°−\mathrm{1}\right)\right) \\ $$$$=\:\mathrm{cos}\:\mathrm{40}°\left(\mathrm{3}−\mathrm{4cos}\:^{\mathrm{2}} \mathrm{40}°\right) \\…