Menu Close

Category: None

Prove-that-sin-36-10-2-5-4-

Question Number 163171 by ZiYangLee last updated on 04/Jan/22 $$\mathrm{Prove}\:\mathrm{that}\:\:\:\mathrm{sin}\:\mathrm{36}°\:=\:\frac{\sqrt{\mathrm{10}−\mathrm{2}\sqrt{\mathrm{5}^{} }}}{\mathrm{4}} \\ $$ Answered by mr W last updated on 04/Jan/22 $$\mathrm{sin}\:\left(\mathrm{3}×\mathrm{18}^{°} \right)=\mathrm{sin}\:\left(\mathrm{54}°\right)=\mathrm{cos}\:\left(\mathrm{36}°\right)=\mathrm{cos}\:\left(\mathrm{2}×\mathrm{18}°\right) \\ $$$$\mathrm{3}\:\mathrm{sin}\:\mathrm{18}°−\mathrm{4}\:\mathrm{sin}^{\mathrm{3}}…

show-that-cos-x-y-cos-x-y-1-tanxtany-1-tanxtany-

Question Number 163153 by MathsFan last updated on 04/Jan/22 $${show}\:{that} \\ $$$$\:\frac{{cos}\left({x}−{y}\right)}{{cos}\left({x}+{y}\right)}=\frac{\mathrm{1}+{tanxtany}}{\mathrm{1}−{tanxtany}} \\ $$ Answered by cortano1 last updated on 04/Jan/22 $$\:{RHS}\::\:\frac{\mathrm{cos}\:{x}\mathrm{cos}\:{y}+\mathrm{sin}\:{x}\mathrm{sin}\:{y}}{\mathrm{cos}\:{x}\mathrm{cos}\:{y}−\mathrm{sin}\:{x}\mathrm{sin}\:{y}}\: \\ $$$$\:\:\:\:\:\:\:\:=\:\frac{\mathrm{cos}\:\left({x}−{y}\right)}{\mathrm{cos}\:\left({x}+{y}\right)} \\…

find-the-integration-sin-x-dx-

Question Number 97590 by bhuvanmahant last updated on 08/Jun/20 $$\mathrm{find}\:\mathrm{the}\:\mathrm{integration} \\ $$$$\int\sqrt{{sin}\left({x}\right)}{dx} \\ $$ Answered by smridha last updated on 09/Jun/20 $$\boldsymbol{{let}}\:..\boldsymbol{{sin}}\left(\boldsymbol{{x}}\right)=\boldsymbol{{u}}^{\mathrm{2}} \\ $$$$\boldsymbol{{so}}\:\int\mathrm{2}{u}^{\mathrm{2}} \left(\mathrm{1}−\boldsymbol{{u}}^{\mathrm{4}}…

Question-163120

Question Number 163120 by ZiYangLee last updated on 04/Jan/22 Answered by Rasheed.Sindhi last updated on 04/Jan/22 $${a}_{\mathrm{1}} =\mathrm{7},\:{a}_{{n}} =\frac{\mathrm{12}{a}_{{n}−\mathrm{1}} }{\mathrm{37}−\left({a}_{{n}−\mathrm{1}} \right)^{\mathrm{2}} }\:{for}\:{n}\geqslant\mathrm{2} \\ $$$${S}={a}_{\mathrm{1}} +\mathrm{2}{a}_{\mathrm{2}}…

Please-dear-members-concerning-this-App-How-to-change-the-color-of-the-paper-on-which-we-are-writing-for-example-from-white-to-any-kind-of-color-

Question Number 163126 by Diels last updated on 04/Jan/22 $$\:\boldsymbol{{Please}}\:\boldsymbol{{dear}}\:\boldsymbol{{members}}.\:\boldsymbol{{concerning}}\:\boldsymbol{{this}}\:\boldsymbol{{App}} \\ $$$$\:\boldsymbol{{How}}\:\boldsymbol{{to}}\:\boldsymbol{{change}}\:\boldsymbol{{the}}\:\boldsymbol{{color}}\: \\ $$$$\:\boldsymbol{{of}}\:\boldsymbol{{the}}\:\boldsymbol{{paper}}\:\boldsymbol{{on}}\:\boldsymbol{{which}}\:\boldsymbol{{we}}\:\boldsymbol{{are}} \\ $$$$\:\boldsymbol{{writing}}\left(\boldsymbol{{for}}\:\boldsymbol{{example}}\:\boldsymbol{{from}}\:\boldsymbol{{white}}\:\boldsymbol{{to}}\:\boldsymbol{{any}}\:\boldsymbol{{kind}}\right. \\ $$$$\left.\:\:\boldsymbol{{of}}\:\boldsymbol{{color}}\right)?????? \\ $$ Commented by mr W last…

Question-163110

Question Number 163110 by ampomahlosotho last updated on 03/Jan/22 Answered by mahdipoor last updated on 03/Jan/22 $$\mathrm{2}^{{x}−\mathrm{2}} =\mathrm{8}{x}\Rightarrow\frac{\mathrm{1}}{\mathrm{32}}\mathrm{2}^{{x}} ={x}\Rightarrow−\frac{\mathrm{1}}{\mathrm{32}×{ln}\mathrm{2}}=\left(−\frac{{x}}{{ln}\mathrm{2}}\right)\mathrm{2}^{\left(−{x}\right)} = \\ $$$$\left(−\frac{{x}}{{ln}\mathrm{2}}\right)\mathrm{2}^{{ln}\mathrm{2}×\frac{−{x}}{{ln}\mathrm{2}}} =\left(−\frac{{x}}{{ln}\mathrm{2}}\right){e}^{\left(\frac{−{x}}{{ln}\mathrm{2}}\right)} \Rightarrow \\…