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cos20-cos40-cos80-

Question Number 103299 by B. H 28 last updated on 14/Jul/20 $${cos}\mathrm{20}°{cos}\mathrm{40}°{cos}\mathrm{80}°=…? \\ $$ Answered by bemath last updated on 14/Jul/20 $$\frac{\mathrm{1}}{\mathrm{4}}\:\mathrm{cos}\:\mathrm{3}\theta\:=\:\frac{\mathrm{1}}{\mathrm{4}}×\mathrm{cos}\:\mathrm{3}.\mathrm{20}^{{o}} =\frac{\mathrm{1}}{\mathrm{4}}×\frac{\mathrm{1}}{\mathrm{2}}\:=\:\frac{\mathrm{1}}{\mathrm{8}} \\ $$…

Given-the-angle-x-construct-the-angle-y-if-1-sin-y-2-sin-x-2-tan-y-3-tan-x-3-cos-y-1-2-cos-x-4-sec-y-cosec-x-hey-do-not-construct-it-just-find-it-out-the-y-for-the-every-given-ca

Question Number 37750 by kunal1234523 last updated on 17/Jun/18 $$\mathrm{Given}\:\mathrm{the}\:\mathrm{angle}\:{x},\:\mathrm{construct}\:\mathrm{the}\:\mathrm{angle}\:{y}\:\mathrm{if}\: \\ $$$$\left(\mathrm{1}\right)\:\mathrm{sin}\:{y}\:=\:\mathrm{2}\:\mathrm{sin}\:{x} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{tan}\:{y}\:=\:\mathrm{3}\:\mathrm{tan}\:{x} \\ $$$$\left(\mathrm{3}\right)\:\mathrm{cos}\:{y}\:=\:\frac{\mathrm{1}}{\mathrm{2}}\mathrm{cos}\:{x}\: \\ $$$$\left(\mathrm{4}\right)\:\mathrm{sec}\:{y}\:=\:\mathrm{cosec}\:{x} \\ $$$$\mathrm{hey}\:\mathrm{do}\:\mathrm{not}\:\mathrm{construct}\:\mathrm{it}\:\mathrm{just}\:\mathrm{find}\:\mathrm{it}\:\mathrm{out}\:\mathrm{the}\:\angle{y}\: \\ $$$$\mathrm{for}\:\mathrm{the}\:\mathrm{every}\:\mathrm{given}\:\mathrm{cases} \\ $$ Commented…

given-a-2-lt-1-now-a-lt-1-or-a-lt-1-a-lt-1-and-a-lt-1-but-but-its-false-we-know-if-a-2-lt-1-so-1-lt-a-lt-1-so-my-question-is-why-this-is-happening-at-all-

Question Number 37738 by kunal1234523 last updated on 17/Jun/18 $$\mathrm{given}\:{a}^{\mathrm{2}} <\mathrm{1} \\ $$$$\mathrm{now} \\ $$$${a}<\sqrt{\mathrm{1}} \\ $$$$\mathrm{or}\:{a}<\pm\mathrm{1} \\ $$$$\therefore\:{a}<\mathrm{1}\:\mathrm{and}\:{a}<−\mathrm{1}\:\:\:\:\mathrm{but}\:\mathrm{but}\:\mathrm{its}\:\mathrm{false}\:\mathrm{we}\:\mathrm{know} \\ $$$${if}\:\mathrm{a}^{\mathrm{2}} <\mathrm{1}\:\mathrm{so}\:−\mathrm{1}<{a}<\mathrm{1}\: \\ $$$${so}\:{my}\:{question}\:{is}\:{why}\:{this}\:{is}\:{happening}\:{at}\:{all}. \\…

Question-103239

Question Number 103239 by 9027201563 last updated on 13/Jul/20 Answered by OlafThorendsen last updated on 13/Jul/20 $$\mathrm{100}\:\mathrm{N}\:×\mathrm{cos45}°+\mathrm{60}\:\mathrm{N}\:=\:\mathrm{10}\:\mathrm{kg}\:×{a} \\ $$$${a}\:=\:\mathrm{10cos45}°+\mathrm{6}\:\approx\:\mathrm{13},\mathrm{1}\:\mathrm{m}.\mathrm{s}^{−\mathrm{2}} \\ $$$$\Rightarrow\:\boldsymbol{\mathrm{B}} \\ $$ Commented by…

Sir-Aifour-I-just-answered-your-question-number-37209-greetings-from-a-rainy-Saturday-evening-in-Vienna-Austria-

Question Number 37691 by MJS last updated on 16/Jun/18 $$\mathrm{Sir}\:\mathrm{Aifour},\:\mathrm{I}\:\mathrm{just}\:\mathrm{answered}\:\mathrm{your}\:\mathrm{question} \\ $$$$\mathrm{number}\:\mathrm{37209}…\:\mathrm{greetings}\:\mathrm{from}\:\mathrm{a}\:\mathrm{rainy} \\ $$$$\mathrm{Saturday}\:\mathrm{evening}\:\mathrm{in}\:\mathrm{Vienna},\:\mathrm{Austria}! \\ $$ Commented by ajfour last updated on 16/Jun/18 $${rainy}\:{even}\:{up}\:{here},\:{Sir} \\…

Question-103205

Question Number 103205 by DGmichael last updated on 13/Jul/20 Answered by OlafThorendsen last updated on 13/Jul/20 $${f}\left(\lambda\right)\:=\:\underset{{k}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{\lambda^{{k}} }{{k}!} \\ $$$$\Rightarrow\:{f}'\left(\lambda\right)\:=\:\underset{{k}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{{k}\lambda^{{k}−\mathrm{1}} }{{k}!}\:=\:\underset{{k}=\mathrm{1}}…

A-car-of-mass-1000kg-has-an-engine-capable-of-developing-power-of-15Kw-against-a-constand-Resistance-R-N-The-maximum-speed-of-the-car-on-level-road-is-100-3-ms-1-Calculate-the-value-of-R-Gi

Question Number 37652 by Rio Mike last updated on 16/Jun/18 $$\mathrm{A}\:\mathrm{car},\mathrm{of}\:\mathrm{mass}\:\mathrm{1000kg},\mathrm{has}\:\mathrm{an}\:\mathrm{engine} \\ $$$$\mathrm{capable}\:\mathrm{of}\:\mathrm{developing}\:\mathrm{power}\:\mathrm{of}\: \\ $$$$\mathrm{15Kw}\:\mathrm{against}\:\mathrm{a}\:\mathrm{constand}\:\mathrm{Resistance} \\ $$$$\mathrm{R}\:\mathrm{N}.\mathrm{The}\:\mathrm{maximum}\:\mathrm{speed}\:\mathrm{of}\:\mathrm{the}\:\mathrm{car} \\ $$$$\mathrm{on}\:\mathrm{level}\:\mathrm{road}\:\mathrm{is}\:\frac{\mathrm{100}}{\mathrm{3}}\:{ms}^{−\mathrm{1}} \: \\ $$$$\mathrm{Calculate}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{R}. \\ $$$$\mathrm{Given}\:\mathrm{that}\:\mathrm{the}\:\mathrm{resistance}\:\mathrm{and}\:\mathrm{the}\:\mathrm{power} \\…