Question Number 13143 by tawa tawa last updated on 15/May/17 $$\mathrm{Find}\:\mathrm{the}\:\mathrm{point}\:\left(\mathrm{x},\mathrm{y}\right)\:\mathrm{which}\:\mathrm{lies}\:\mathrm{8}\:\mathrm{unit}\:\mathrm{from}\:\mathrm{the}\:\mathrm{origin},\:\:\mathrm{along}\:\mathrm{the}\:\mathrm{terminal}\:\mathrm{line} \\ $$$$\mathrm{of}\:\mathrm{155}°.\: \\ $$ Commented by RasheedSindhi last updated on 15/May/17 $$\mathrm{x}^{\mathrm{2}} +\mathrm{y}^{\mathrm{2}} =\mathrm{8}^{\mathrm{2}}…
Question Number 13142 by tawa tawa last updated on 15/May/17 $$\mathrm{Find}\:\mathrm{the}\:\mathrm{height}\:\mathrm{PQ}\:\mathrm{of}\:\mathrm{a}\:\mathrm{tower}\:\mathrm{of}\:\mathrm{an}\:\mathrm{observant}\:\mathrm{at}\:\mathrm{a}\:\mathrm{point}\:\mathrm{O},\:\mathrm{135}\:\mathrm{m}\:\mathrm{from}\:\mathrm{the} \\ $$$$\mathrm{foot}\:\mathrm{of}\:\mathrm{the}\:\mathrm{tower}.\:\mathrm{Determine}\:\mathrm{the}\:\mathrm{angle}\:\mathrm{of}\:\mathrm{elevation}\:\mathrm{of}\:\mathrm{the}\:\mathrm{tower}. \\ $$ Commented by RasheedSindhi last updated on 15/May/17 $$\mathrm{One}\:\mathrm{of}\:\mathrm{the}\:\mathrm{two}\:\left(\mathrm{height}\:\mathrm{of}\:\mathrm{tower}\right. \\ $$$$\left.\mathrm{or}\:\:\mathrm{angle}\:\mathrm{of}\:\mathrm{elevation}\right)\:\mathrm{must}…
Question Number 78643 by thiruppathit883@gmail.com last updated on 19/Jan/20 $$\mathrm{sin}\:\mathrm{20}×\mathrm{sin}\:\mathrm{40}×\mathrm{sin}\:\mathrm{80}=\sqrt{\mathrm{3}/\mathrm{8}} \\ $$ Commented by jagoll last updated on 19/Jan/20 $$\mathrm{using}\:\mathrm{formula} \\ $$$$\mathrm{sin}\:\theta×\mathrm{sin}\:\left(\mathrm{60}^{\mathrm{o}} −\theta\right)×\mathrm{sin}\:\left(\mathrm{60}^{\mathrm{o}} +\theta\right)= \\…
Question Number 144169 by gsk2684 last updated on 22/Jun/21 $$\mathrm{please}\:\mathrm{find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\: \\ $$$$\mathrm{sin}\:\frac{\mathrm{2}\Pi}{\mathrm{7}}+\mathrm{sin}\:\frac{\mathrm{4}\Pi}{\mathrm{7}}+\mathrm{sin}\:\frac{\mathrm{8}\Pi}{\mathrm{7}} \\ $$ Commented by justtry last updated on 23/Jun/21 Answered by mindispower last…
Question Number 144164 by bobhans last updated on 22/Jun/21 $$\mathrm{In}\:\Delta\mathrm{ABC}\:\mathrm{given}\:\mathrm{a}=\mathrm{5},\:\mathrm{b}=\mathrm{7}\:\&\:\mathrm{c}=\:\mathrm{4}. \\ $$$$\mathrm{If}\:\measuredangle\mathrm{CAB}\:=\:\alpha\:\mathrm{then}\:\mathrm{cot}\:\left(\frac{\mathrm{1}}{\mathrm{2}}\alpha\right)=? \\ $$ Answered by liberty last updated on 22/Jun/21 $$\mathrm{cot}\:\left(\frac{\mathrm{1}}{\mathrm{2}}\alpha\right)\:=\:\sqrt{\frac{\mathrm{s}\left(\mathrm{s}−\mathrm{a}\right)}{\left(\mathrm{s}−\mathrm{b}\right)\left(\mathrm{s}−\mathrm{c}\right)}} \\ $$$$\mathrm{where}\:\mathrm{s}\:=\:\frac{\mathrm{a}+\mathrm{b}+\mathrm{c}}{\mathrm{2}}=\frac{\mathrm{5}+\mathrm{7}+\mathrm{4}}{\mathrm{2}}=\mathrm{8} \\…
Question Number 144162 by bobhans last updated on 22/Jun/21 Commented by Rasheed.Sindhi last updated on 22/Jun/21 $$\mathcal{E}{xternal}\:{angle}\:{of}\:{pentagon} \\ $$$$\:\:\:\:\:\:=\mathrm{180}−\mathrm{108}=\mathrm{72} \\ $$$${x}+\mathrm{72}+\mathrm{72}=\mathrm{180} \\ $$$${x}=\mathrm{36} \\ $$…
Question Number 144139 by bobhans last updated on 22/Jun/21 Answered by liberty last updated on 22/Jun/21 Commented by EDWIN88 last updated on 22/Jun/21 $$\frac{\mathrm{4}}{\mathrm{R}}\:=\:\frac{\mathrm{8}}{\mathrm{12}+\mathrm{R}}\:\Rightarrow\frac{\mathrm{1}}{\mathrm{R}}=\frac{\mathrm{2}}{\mathrm{12}+\mathrm{R}}\:;\:\mathrm{R}=\mathrm{12} \\…
Question Number 144086 by liberty last updated on 21/Jun/21 $$\mathrm{If}\:\mathrm{sin}\:\mathrm{t}\:+\:\mathrm{cos}\:\:\mathrm{t}\:=\:\frac{\mathrm{2}}{\mathrm{3}}\:\mathrm{then}\:\mathrm{cosec}\:\mathrm{t}+\mathrm{sec}\:\mathrm{t}\:=? \\ $$ Answered by bobhans last updated on 21/Jun/21 $$\Leftrightarrow\:\mathrm{1}+\mathrm{2sin}\:\mathrm{t}\:\mathrm{cos}\:\mathrm{t}\:=\:\frac{\mathrm{4}}{\mathrm{9}} \\ $$$$\Rightarrow\:\mathrm{2sin}\:\mathrm{t}\:\mathrm{cos}\:\mathrm{t}\:=−\frac{\mathrm{5}}{\mathrm{9}} \\ $$$$\Rightarrow\mathrm{sin}\:\mathrm{t}\:\mathrm{cos}\:\mathrm{t}\:=−\frac{\mathrm{5}}{\mathrm{18}} \\…
Question Number 131492 by Ar Brandon last updated on 05/Feb/21 $$\mathrm{sin}^{\mathrm{4}} \frac{\pi}{\mathrm{16}}+\mathrm{sin}^{\mathrm{4}} \frac{\mathrm{3}\pi}{\mathrm{16}}+\mathrm{sin}^{\mathrm{4}} \frac{\mathrm{5}\pi}{\mathrm{16}}+\mathrm{sin}^{\mathrm{4}} \frac{\mathrm{7}\pi}{\mathrm{16}} \\ $$ Answered by Dwaipayan Shikari last updated on 05/Feb/21…
Question Number 65929 by Masumsiddiqui399@gmail.com last updated on 06/Aug/19 Commented by kaivan.ahmadi last updated on 06/Aug/19 $${cot}\mathrm{1}={tan}\mathrm{89} \\ $$$${cot}\mathrm{2}={tan}\mathrm{88} \\ $$$$\vdots \\ $$$${cot}\mathrm{44}={tan}\mathrm{46} \\ $$$${since}\:\:{tan}\left(\frac{\pi}{\mathrm{2}}−\alpha\right)={cot}\alpha…