Question Number 166169 by cortano1 last updated on 14/Feb/22 $$\:\:\mathrm{sin}^{\mathrm{7}} \left(\mathrm{x}\right)+\frac{\mathrm{1}}{\mathrm{sin}\:^{\mathrm{3}} \left(\mathrm{x}\right)}=\mathrm{cos}\:^{\mathrm{7}} \left(\mathrm{x}\right)+\frac{\mathrm{1}}{\mathrm{cos}\:^{\mathrm{3}} \left(\mathrm{x}\right)} \\ $$$$ \\ $$ Answered by greogoury55 last updated on 14/Feb/22…
Question Number 166170 by mathls last updated on 14/Feb/22 $${tan}\left({a}+{b}\right)=\frac{\mathrm{1}}{\mathrm{17}}\:\:\:,\:\:\:{tan}\left({a}−{b}\right)=\frac{\mathrm{11}}{\mathrm{13}} \\ $$$${tan}\mathrm{2}{a}=?\:\:\:\:\:\:{tan}\mathrm{2}{b}=? \\ $$ Answered by cortano1 last updated on 14/Feb/22 $$\Rightarrow\mathrm{2}{a}\:=\:\left({a}+{b}\right)+\left({a}−{b}\right) \\ $$$$\Rightarrow\mathrm{tan}\:\mathrm{2}{a}\:=\frac{\frac{\mathrm{1}}{\mathrm{17}}+\frac{\mathrm{11}}{\mathrm{13}}}{\mathrm{1}−\frac{\mathrm{1}}{\mathrm{17}}.\frac{\mathrm{11}}{\mathrm{13}}}\:=\:\frac{\mathrm{20}}{\mathrm{21}} \\…
Question Number 100522 by bemath last updated on 27/Jun/20 Answered by bramlex last updated on 27/Jun/20 Commented by bramlex last updated on 27/Jun/20 $$\left(\mathrm{1}\right)\pi−\alpha\:+\:\pi−\beta\:+\:{x}\:+\:{y}\:=\:\mathrm{2}\pi \\…
Question Number 34980 by NECx last updated on 14/May/18 $${If}\:{cos}\mathrm{45}°\:=\frac{\mathrm{1}}{\:\sqrt{\mathrm{2}}}\:.\:{Find}\:{cos}\mathrm{45}.\mathrm{1}° \\ $$ Answered by ajfour last updated on 14/May/18 $$\mathrm{cos}\:\left(\frac{\pi}{\mathrm{4}}+\frac{\pi}{\mathrm{1800}}\right)\approx\mathrm{cos}\:\left(\frac{\pi}{\mathrm{4}}\right)−\frac{\pi}{\mathrm{1800}}\mathrm{sin}\:\frac{\pi}{\mathrm{4}} \\ $$$$\:\:\:\:=\frac{\mathrm{1}}{\:\sqrt{\mathrm{2}}}\left(\mathrm{1}−\frac{\pi}{\mathrm{1800}}\right)\:=\mathrm{0}.\mathrm{707}\left(\mathrm{1}−\frac{\mathrm{0}.\mathrm{0314}}{\mathrm{18}}\right) \\ $$$$\:\:\:=\mathrm{0}.\mathrm{707}\left(\mathrm{1}−\mathrm{0}.\mathrm{00173}\right) \\…
Question Number 100491 by bobhans last updated on 27/Jun/20 Answered by bramlex last updated on 27/Jun/20 $${let}\:\mathrm{arccot}\:\frac{\mathrm{1}}{\mathrm{2}}\:=\:{z}\:\Rightarrow\:\mathrm{cot}\:{z}\:=\:\frac{\mathrm{1}}{\mathrm{2}} \\ $$$${let}\:\mathrm{arccot}\:\frac{\mathrm{2}}{\mathrm{3}}\:=\:{w}\:\Rightarrow\mathrm{cot}\:{w}\:=\:\frac{\mathrm{2}}{\mathrm{3}} \\ $$$$\Leftrightarrow\mathrm{tan}\:\left({z}+{w}\right)\:=\:\frac{\mathrm{tan}\:{z}+\mathrm{tan}\:{w}}{\mathrm{1}−\mathrm{tan}\:{z}.\mathrm{tan}\:{w}} \\ $$$$=\:\frac{\mathrm{2}+\frac{\mathrm{3}}{\mathrm{2}}}{\mathrm{1}−\mathrm{2}.\frac{\mathrm{3}}{\mathrm{2}}}\:=\:\frac{\mathrm{7}}{\mathrm{2}−\mathrm{6}}\:=\:−\frac{\mathrm{7}}{\mathrm{4}\:}\:\blacksquare\: \\ $$…
Question Number 166013 by mathlove last updated on 11/Feb/22 Answered by JDamian last updated on 11/Feb/22 $${x}_{{r}} ={e}^{{i}\frac{\pi}{\mathrm{2}^{{r}} }} \\ $$$${x}_{\mathrm{1}} {x}_{\mathrm{2}} {x}_{\mathrm{3}} \centerdot\centerdot\centerdot{x}_{\infty} =\:{e}^{{i}\pi\underset{{r}}…
Question Number 165995 by mathlove last updated on 11/Feb/22 $$\begin{cases}{{sinx}+{siny}=\frac{\mathrm{3}}{\mathrm{2}}}\\{\mathrm{2}^{\mathrm{sin}\:{x}} +\mathrm{2}^{\mathrm{sin}\:{y}} =\mathrm{2}+\sqrt{\mathrm{2}}}\end{cases}\:\:\:\:\:\:\:{faind}\:\:\:{x}=? \\ $$ Answered by alephzero last updated on 11/Feb/22 $$\begin{cases}{\mathrm{sin}\:{x}\:+\:\mathrm{cos}\:{y}\:=\:\frac{\mathrm{3}}{\mathrm{2}}}\\{\mathrm{2}^{\mathrm{sin}\:{x}} +\:\mathrm{2}^{\mathrm{cos}\:{y}} \:=\:\mathrm{2}\:+\:\sqrt{\mathrm{2}}}\end{cases} \\…
Question Number 100436 by Dwaipayan Shikari last updated on 26/Jun/20 $$\alpha=\frac{\mathrm{2}\pi}{\mathrm{7}} \\ $$$$\mathrm{Find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\: \\ $$$$\mathrm{tan}\alpha\mathrm{tan2}\alpha+\mathrm{tan2}\alpha\mathrm{tan4}\alpha+\mathrm{tan}\alpha\mathrm{tan4}\alpha \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com
Question Number 34671 by math khazana by abdo last updated on 09/May/18 $${calculste}\:\sum_{{n}=\mathrm{1}} ^{\infty} \:\:{arctan}\left(\frac{\mathrm{2}}{{n}^{\mathrm{2}} }\right). \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com
Question Number 165737 by amin96 last updated on 07/Feb/22 $$ \\ $$Let alpha is acute angle and cos alpha=3/5 prove that alpha is not r.π…