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Category: Trigonometry

Determine-the-cardinality-and-power-set-of-B-a-b-c-d-e-f-g-h-i-

Question Number 159071 by physicstutes last updated on 12/Nov/21 $$\mathrm{Determine}\:\mathrm{the}\:\mathrm{cardinality}\:\mathrm{and}\:\mathrm{power} \\ $$$$\mathrm{set}\:\mathrm{of} \\ $$$${B}\:=\:\left\{\left\{{a},{b},{c}\right\},\left\{{d},{e}\right\},\left\{{f},{g},{h},{i}\right\}\right. \\ $$ Answered by Rasheed.Sindhi last updated on 12/Nov/21 $$\mathrm{cardinality}\:\mathrm{of}\:\mathrm{B}=\mathrm{3},\:\mathrm{because}\:\mathrm{B} \\…

For-R-cos-cosx-siny-sinx-x-R-then-find-the-sum-of-the-possible-values-of-sin-siny-

Question Number 27958 by bmind4860 last updated on 17/Jan/18 $${For}\:\alpha\in{R},\:{cos}\alpha{cosx}+{siny}\geqslant{sinx},\:\forall{x}\in{R}, \\ $$$${then}\:{find}\:{the}\:{sum}\:{of}\:{the}\:{possible}\:{values} \\ $$$${of}\:{sin}\alpha+{siny}. \\ $$ Answered by ajfour last updated on 17/Jan/18 $$\:\:\:\:\mathrm{sin}\:{y}\:\geqslant\:\mathrm{sin}\:{x}−\mathrm{cos}\:\alpha\mathrm{cos}\:{x} \\…

arcsin-cos-93-2-

Question Number 159030 by cortano last updated on 12/Nov/21 $$\:\left(\mathrm{arcsin}\:\left(\mathrm{cos}\:\mathrm{93}°\right)\right)^{\mathrm{2}} =? \\ $$ Answered by mr W last updated on 12/Nov/21 $$\mathrm{cos}\:\mathrm{93}°=−\mathrm{sin}\:\mathrm{3}°=−\mathrm{sin}\:\left(\frac{\pi}{\mathrm{60}}\right) \\ $$$${arcsin}\left(\mathrm{cos}\:\mathrm{93}°\right)={arcsin}\left(−\mathrm{sin}\:\frac{\pi}{\mathrm{60}}\right)=−\frac{\pi}{\mathrm{60}} \\…

Question-27850

Question Number 27850 by v7277668420 last updated on 15/Jan/18 Answered by bmind4860 last updated on 15/Jan/18 $${a}^{\mathrm{2}} {sec}^{\mathrm{2}} \theta−{b}^{\mathrm{2}} \left({sec}^{\mathrm{2}} \theta−\mathrm{1}\right)={c}^{\mathrm{2}} \\ $$$${after}\:{rearranging}\:{we}\:{have} \\ $$$${sec}^{\mathrm{2}}…

sinx-sin3x-sin-x-0-then-find-the-general-solution-

Question Number 27843 by bmind4860 last updated on 15/Jan/18 $${sinx}+{sin}\mathrm{3}{x}+{sin}\sqrt{{x}}=\mathrm{0},\:{then}\:{find}\:{the}\: \\ $$$${general}\:{solution}? \\ $$ Commented by abdo imad last updated on 17/Jan/18 $${let}\:{put}\:\sqrt{{x}}={t}\:\:\:{e}\Leftrightarrow\:\:{sint}\:+\:{sin}\left({t}^{\mathrm{2}} \right)\:\:+{sin}\left(\mathrm{3}{t}^{\mathrm{2}} \right)\:{general}\:{case}…

If-xcos-ycos-2pi-3-zcos-4pi-3-then-the-value-of-xy-yz-zx-

Question Number 27840 by bmind4860 last updated on 15/Jan/18 $${If}\:{xcos}\theta={ycos}\left(\theta+\frac{\mathrm{2}\pi}{\mathrm{3}}\right)={zcos}\left(\theta+\frac{\mathrm{4}\pi}{\mathrm{3}}\right),{then} \\ $$$${the}\:{value}\:{of}\:{xy}+{yz}+{zx}. \\ $$ Answered by ajfour last updated on 15/Jan/18 $${let}\:\:\:\:{x}\mathrm{cos}\:\theta={y}\mathrm{cos}\:\left(\theta+\frac{\mathrm{2}\pi}{\mathrm{3}}\right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:={z}\mathrm{cos}\:\left(\theta+\frac{\mathrm{4}\pi}{\mathrm{3}}\right)={r}\: \\…