Question Number 18092 by Tinkutara last updated on 15/Jul/17 $$\mathrm{A}\:\mathrm{value}\:\mathrm{of}\:\theta\:\mathrm{satisfying} \\ $$$$\mathrm{4cos}^{\mathrm{2}} \theta\mathrm{sin}\theta\:−\:\mathrm{2sin}^{\mathrm{2}} \theta\:=\:\mathrm{3sin}\theta\:\mathrm{is} \\ $$$$\left(\mathrm{1}\right)\:\frac{\mathrm{9}\pi}{\mathrm{10}} \\ $$$$\left(\mathrm{2}\right)\:\frac{\pi}{\mathrm{10}} \\ $$$$\left(\mathrm{3}\right)\:−\frac{\mathrm{13}\pi}{\mathrm{10}} \\ $$$$\left(\mathrm{4}\right)\:−\frac{\mathrm{17}\pi}{\mathrm{10}} \\ $$ Answered…
Question Number 18069 by tawa tawa last updated on 14/Jul/17 $$\left.\mathrm{ai}\right)\:\:\mathrm{If}\:\theta\:\mathrm{is}\:\mathrm{the}\:\mathrm{angle}\:\mathrm{in}\:\mathrm{the}\:\mathrm{fourth}\:\mathrm{quadrant}\:\mathrm{satisfying}\:\mathrm{the}\:\mathrm{equation}\::\:\mathrm{cot}^{\mathrm{2}} \theta\:=\:\mathrm{4} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\mathrm{find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{the}\:\mathrm{function}:\:\:\mathrm{f}\left(\theta\right)\:=\:\frac{\mathrm{1}}{\:\sqrt{\mathrm{5}}}\:\left(\mathrm{sec}\theta\:−\:\mathrm{cosec}\theta\right) \\ $$$$\left.\mathrm{aii}\right)\:\:\mathrm{Prove}\:\mathrm{that}:\:\:\:\sqrt{\frac{\mathrm{1}\:+\:\mathrm{cos}\theta}{\mathrm{1}\:−\:\mathrm{cos}\theta}}\:\:=\:\:\mathrm{cosec}\theta\:+\:\mathrm{cot}\theta,\:\:\:\:\:\:\:\:\mathrm{if}\:\:\mathrm{cos}\theta\:\neq\:\mathrm{1} \\ $$$$\left(\mathrm{b}\right)\:\:\:\mathrm{Let}\:\:\mathrm{R}\:\mathrm{be}\:\mathrm{a}\:\mathrm{positive}\:\mathrm{real}\:\mathrm{number}\:\mathrm{and}\:\mathrm{let}\:\alpha\:\mathrm{satisfy}\:\mathrm{the}\:\mathrm{inequality}\: \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\mathrm{0}\:<\:\alpha\:<\:\mathrm{360}.\:\mathrm{express}\:\mathrm{the}\:\mathrm{function}\:\:\mathrm{2sin}\theta\:+\:\mathrm{cos}\theta\:\mathrm{in}\:\mathrm{the}\:\mathrm{form}\:\:\mathrm{Rsin}\left(\theta\:+\:\alpha\right). \\ $$$$\:\:\:\:\:\:\:\:\:\:\mathrm{Hence},\:\mathrm{find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\theta\:\mathrm{between}\:\mathrm{0}\:\mathrm{and}\:\mathrm{360}\:\mathrm{which}\:\mathrm{satisfy}\:\mathrm{the}\:\mathrm{equation}. \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{3cos}\theta\:+\:\mathrm{6sin}\theta\:=\:\mathrm{1} \\…
Question Number 18062 by Tinkutara last updated on 14/Jul/17 $$\mathrm{If}\:\mathrm{0}\:<\:\alpha,\:\beta\:<\:\pi\:\mathrm{and}\:\mathrm{they}\:\mathrm{satisfy} \\ $$$$\mathrm{cos}\:\alpha\:+\:\mathrm{cos}\:\beta\:−\:\mathrm{cos}\:\left(\alpha\:+\:\beta\right)\:=\:\frac{\mathrm{3}}{\mathrm{2}} \\ $$$$\left(\mathrm{1}\right)\:\alpha\:=\:\beta \\ $$$$\left(\mathrm{2}\right)\:\alpha\:+\:\beta\:=\:\frac{\mathrm{2}\pi}{\mathrm{3}} \\ $$$$\left(\mathrm{3}\right)\:\alpha\:=\:\mathrm{2}\beta \\ $$$$\left(\mathrm{4}\right)\:\beta\:=\:\mathrm{2}\alpha \\ $$ Answered by Tinkutara…
Question Number 18063 by Tinkutara last updated on 14/Jul/17 $$\mathrm{The}\:\mathrm{angles}\:{A},\:{B},\:{C}\:\mathrm{of}\:\mathrm{a}\:\mathrm{triangle}\:{ABC} \\ $$$$\mathrm{satisfy}\:\mathrm{4cos}{A}\mathrm{cos}{B}\:+\:\mathrm{sin2}{A}\:+\:\mathrm{sin2}{B}\:+ \\ $$$$\mathrm{sin2}{C}\:=\:\mathrm{4}.\:\mathrm{Then}\:\mathrm{which}\:\mathrm{of}\:\mathrm{the}\:\mathrm{following} \\ $$$$\mathrm{statements}\:\mathrm{is}/\mathrm{are}\:\mathrm{correct}? \\ $$$$\left(\mathrm{1}\right)\:\mathrm{The}\:\mathrm{triangle}\:{ABC}\:\mathrm{is}\:\mathrm{right}\:\mathrm{angled} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{The}\:\mathrm{triangle}\:{ABC}\:\mathrm{is}\:\mathrm{isosceles} \\ $$$$\left(\mathrm{3}\right)\:\mathrm{The}\:\mathrm{triangle}\:{ABC}\:\mathrm{is}\:\mathrm{neither} \\ $$$$\mathrm{isosceles}\:\mathrm{nor}\:\mathrm{right}\:\mathrm{angled} \\…
Question Number 83591 by jagoll last updated on 04/Mar/20 $$\mathrm{3x}^{\mathrm{2}} −\mathrm{x}+\left(\mathrm{t}^{\mathrm{2}} −\mathrm{4t}+\mathrm{3}\right)\:=\:\mathrm{0} \\ $$$$\mathrm{has}\:\mathrm{a}\:\mathrm{roots}\:\mathrm{sin}\:\alpha\:\mathrm{and}\:\mathrm{cos}\:\alpha. \\ $$$$\mathrm{find}\:\sqrt{\mathrm{t}^{\mathrm{2}} −\mathrm{4t}+\mathrm{5}} \\ $$ Commented by jagoll last updated on…
Question Number 83582 by jagoll last updated on 04/Mar/20 $$\mathrm{Given}\:\mathrm{A}\:=\:\mathrm{580}^{\mathrm{o}} \\ $$$$\mathrm{find}\:\mathrm{sin}\:\left(\frac{\mathrm{A}}{\mathrm{2}}\right)\:\mathrm{in}\:\mathrm{term}\:\mathrm{sin}\:\left(\mathrm{A}\right) \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com
Question Number 18036 by tawa tawa last updated on 14/Jul/17 $$\mathrm{solve}: \\ $$$$ \\ $$$$\mathrm{4cos}\left(\mathrm{x}\right)\:+\:\mathrm{2sin}\left(\mathrm{x}\right)\:=\:\mathrm{2}\:+\:\sqrt{\mathrm{3}} \\ $$ Commented by ajfour last updated on 14/Jul/17 $$\mathrm{several}\:\mathrm{solutions}.…
Question Number 18003 by Tinkutara last updated on 13/Jul/17 $$\mathrm{The}\:\mathrm{value}\:\mathrm{of}\:\mathrm{cos}{A}\centerdot\mathrm{cos2}{A}\centerdot\mathrm{cos2}^{\mathrm{2}} {A}\:…..\:\mathrm{cos}\left(\mathrm{2}^{{n}\:−\:\mathrm{1}} {A}\right), \\ $$$$\mathrm{where}\:{A}\:\in\:{R}\:\mathrm{may}\:\mathrm{be} \\ $$$$\left(\mathrm{1}\right)\:\mathrm{1} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{2} \\ $$$$\left(\mathrm{3}\right)\:−\mathrm{1} \\ $$$$\left(\mathrm{4}\right)\:\frac{\mathrm{sin}\:\mathrm{2}^{{n}} \:{A}}{\mathrm{2}^{{n}} \:\mathrm{sin}\:{A}} \\…
Question Number 17983 by alex041103 last updated on 13/Jul/17 $${Evaluate}\:{cos}\left(\mathrm{20}°\right){cos}\left(\mathrm{40}°\right){cos}\left(\mathrm{80}°\right). \\ $$$${This}\:{question}\:{is}\:{just}\:{for}\:{fun}\:{and}\:{practice}. \\ $$$${Evryone}\:{who}\:{wants}\:{can}\:{answer}\:{this}\:{question}. \\ $$ Answered by ajfour last updated on 13/Jul/17 $$\mathrm{cos}\:\mathrm{20}°\mathrm{cos}\:\mathrm{40}°\mathrm{cos}\:\mathrm{80}°= \\…
Question Number 83513 by jagoll last updated on 03/Mar/20 $$\mathrm{If}\:\mathrm{m}\:\mathrm{tan}\:\left(\theta−\mathrm{30}^{\mathrm{o}} \right)\:=\:\mathrm{n}\:\mathrm{tan}\:\left(\theta+\mathrm{12}^{\mathrm{o}} \right) \\ $$$$\mathrm{prove}\:\mathrm{that}\:\mathrm{cos}\:\mathrm{2}\theta\:=\:\frac{\mathrm{m}+\mathrm{n}}{\mathrm{2}\left(\mathrm{m}−\mathrm{n}\right)} \\ $$ Commented by mind is power last updated on 04/Mar/20…