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Category: Trigonometry

Show-that-tan-58-tan-32-1-

Question Number 160411 by nadovic last updated on 29/Nov/21 $$\:\:\mathrm{Show}\:\mathrm{that}\:\:\mathrm{tan}\:\mathrm{58}°\mathrm{tan}\:\mathrm{32}°\:=\:\mathrm{1} \\ $$ Answered by TheSupreme last updated on 29/Nov/21 $${tan}\left(\alpha\right){tan}\left(\frac{\pi}{\mathrm{2}}−\alpha\right)={tan}\left(\alpha\right){cotan}\left(\alpha\right)=\mathrm{1} \\ $$$$ \\ $$ Terms…

Question-29249

Question Number 29249 by ajfour last updated on 05/Feb/18 Commented by ajfour last updated on 05/Feb/18 $${Find}\:{side}\:{lengths}\:\boldsymbol{{a}},\boldsymbol{{b}},\boldsymbol{{c}}\:\:{of}\:\bigtriangleup{ABC} \\ $$$${in}\:{terms}\:{of}\:\boldsymbol{{r}}_{\mathrm{1}} ,\:\boldsymbol{{r}}_{\mathrm{2}} ,\:{and}\:\boldsymbol{{r}}_{\mathrm{3}} . \\ $$$${We}\:{may}\:{call}\:{r}_{\mathrm{1}} \:{as}\:\boldsymbol{{p}},\:…

find-cos-5-interms-of-cos-then-find-the-value-of-cos-pi-10-

Question Number 29173 by abdo imad last updated on 04/Feb/18 $${find}\:{cos}\left(\mathrm{5}\alpha\right)\:{interms}\:{of}\:{cos}\alpha\:{then}\:{find}\:{the}\:{value}\:{of} \\ $$$${cos}\left(\frac{\pi}{\mathrm{10}}\right). \\ $$ Answered by ajfour last updated on 05/Feb/18 $$\mathrm{cos}\:\mathrm{5}\alpha\:=\mathrm{cos}\:\mathrm{3}\alpha\:\mathrm{cos}\:\mathrm{2}\alpha−\mathrm{sin}\:\mathrm{3}\alpha\:\mathrm{sin}\:\mathrm{2}\alpha \\ $$$$=\left(\mathrm{4cos}\:^{\mathrm{3}}…

If-tan-2-atan-2-b-tan-2-btan-2-c-tan-2-ctan-2-a-2tan-2-atan-2-btan-2-c-1-then-find-the-value-of-sin-2-a-sin-2-b-sin-2-c-

Question Number 29131 by $@ty@m last updated on 04/Feb/18 $${If}\:\mathrm{tan}^{\mathrm{2}} {a}\mathrm{tan}\:^{\mathrm{2}} {b}+\mathrm{tan}^{\mathrm{2}} {b}\mathrm{tan}\:^{\mathrm{2}} {c}+\mathrm{tan}^{\mathrm{2}} {c}\mathrm{tan}\:^{\mathrm{2}} {a} \\ $$$$+\mathrm{2tan}^{\mathrm{2}} {a}\mathrm{tan}^{\mathrm{2}} {b}\mathrm{tan}\:^{\mathrm{2}} {c}=\mathrm{1} \\ $$$${then}\:{find}\:{the}\:{value}\:{of}: \\ $$$$\mathrm{sin}\:^{\mathrm{2}}…