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Category: Trigonometry

2-cos2x-2-cos-2-x-3-2-cos2x-x-i-m-so-sorry-it-s-my-mistake-the-true-question-is-2-cos2x-2-cos-2-x-3-2-cos2pi-

Question Number 10429 by ridwan balatif last updated on 09/Feb/17 $$\mathrm{2}^{\mathrm{cos2x}} +\mathrm{2}^{\mathrm{cos}^{\mathrm{2}} \mathrm{x}} =\mathrm{3}×\mathrm{2}^{−\mathrm{cos2x}} \: \\ $$$$\mathrm{x}=…? \\ $$$$\mathrm{i}'\mathrm{m}\:\mathrm{so}\:\mathrm{sorry},\:\mathrm{it}'\mathrm{s}\:\mathrm{my}\:\mathrm{mistake},\:\mathrm{the}\:\mathrm{true}\:\mathrm{question}\:\mathrm{is} \\ $$$$\mathrm{2}^{\mathrm{cos2x}} +\mathrm{2}^{\mathrm{cos}^{\mathrm{2}} \mathrm{x}} =\mathrm{3}×\mathrm{2}^{−\mathrm{cos2}\pi} \:…

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Question Number 10417 by okhema francis last updated on 08/Feb/17 $${hence}\:{or}\:{other}\mathrm{wise}\:\mathrm{solve}\:\mathrm{sin}\:\mathrm{6}\theta−\mathrm{sin}\:\mathrm{2}\theta=\mathrm{0}\:{for}\:\mathrm{0}\leqslant\theta\leqslant\frac{\pi}{\mathrm{2}}. \\ $$$$ \\ $$ Answered by nume1114 last updated on 08/Feb/17 $$\:\:\:\:\mathrm{sin}\:\left(\alpha+\beta\right)−\mathrm{sin}\:\left(\alpha−\beta\right) \\ $$$$=\left(\mathrm{sin}\:\alpha\mathrm{cos}\:\beta+\mathrm{cos}\:\alpha\mathrm{sin}\:\beta\right)…

Question-141457

Question Number 141457 by gajmer last updated on 19/May/21 Answered by mathmax by abdo last updated on 19/May/21 $$\mathrm{f}\left(\mathrm{x}\right)=\frac{\sqrt{\mathrm{2x}^{\mathrm{2}} +\mathrm{4}}−\sqrt{\mathrm{x}^{\mathrm{2}} +\mathrm{5}}}{\mathrm{x}−\mathrm{1}}\:\Rightarrow \\ $$$$\mathrm{f}\left(\mathrm{x}\right)=\frac{\mid\mathrm{x}\mid\sqrt{\mathrm{2}}\sqrt{\mathrm{1}+\frac{\mathrm{2}}{\mathrm{x}^{\mathrm{2}} }}−\mid\mathrm{x}\mid\sqrt{\mathrm{1}+\frac{\mathrm{5}}{\mathrm{x}^{\mathrm{2}} }}}{\mathrm{x}\left(\mathrm{1}−\frac{\mathrm{1}}{\mathrm{x}}\right)}\:\Rightarrow…

ABC-with-AB-5-BC-7-CA-8-Find-the-value-of-sin-A-sin-B-sin-C-cot-A-2-cot-B-2-cot-C-2-

Question Number 10363 by Joel575 last updated on 05/Feb/17 $$\Delta{ABC}\:\mathrm{with}\:{AB}\:=\:\mathrm{5},\:{BC}\:=\:\mathrm{7},\:{CA}\:=\:\mathrm{8} \\ $$$$\mathrm{Find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of} \\ $$$$\left(\mathrm{sin}\:{A}\:+\:\mathrm{sin}\:{B}\:+\:\mathrm{sin}\:{C}\right)\:.\:\left(\mathrm{cot}\:\frac{{A}}{\mathrm{2}}\:+\:\mathrm{cot}\:\frac{{B}}{\mathrm{2}}\:+\:\mathrm{cot}\:\frac{{C}}{\mathrm{2}}\right) \\ $$ Answered by mrW1 last updated on 06/Feb/17 $${a}={BC}=\mathrm{7} \\…

Question-75901

Question Number 75901 by Master last updated on 20/Dec/19 Answered by MJS last updated on 20/Dec/19 $$\frac{\mathrm{1}}{\mathrm{cos}^{\mathrm{2}} \:{x}}=\mathrm{4tan}\:\mathrm{2}{x} \\ $$$$\frac{\mathrm{1}}{\mathrm{1}+\mathrm{cos}\:\mathrm{2}{x}}=\mathrm{2tan}\:\mathrm{2}{x} \\ $$$${x}=\mathrm{arctan}\:{t} \\ $$$$\frac{{t}^{\mathrm{2}} +\mathrm{1}}{\mathrm{2}}=\frac{\mathrm{4}{t}}{\mathrm{1}−{t}^{\mathrm{2}}…

Find-the-range-of-real-number-of-q-such-that-the-function-f-x-cos-x-q-sin-2-x-5-have-minimum-value-is-5-

Question Number 141412 by bramlexs22 last updated on 18/May/21 $$\:{Find}\:{the}\:{range}\:{of}\:{real}\:{number} \\ $$$${of}\:{q}\:{such}\:{that}\:{the}\:{function}\: \\ $$$$\:{f}\left({x}\right)\:=\:\mathrm{cos}\:{x}\left({q}\:\mathrm{sin}\:^{\mathrm{2}} {x}−\mathrm{5}\right)\:{have} \\ $$$${minimum}\:{value}\:{is}\:−\mathrm{5}\:. \\ $$ Commented by MJS_new last updated on…

From-the-top-of-a-100-m-high-building-a-man-observes-the-top-of-a-tree-at-an-angle-of-depression-30-If-the-tree-is-50-m-tall-the-angle-of-depression-of-the-foot-of-the-tree-is-viewed-by-the-man-is

Question Number 10265 by Tawakalitu ayo mi last updated on 31/Jan/17 $$\mathrm{From}\:\mathrm{the}\:\mathrm{top}\:\mathrm{of}\:\mathrm{a}\:\mathrm{100}\:\mathrm{m}\:\mathrm{high}\:\mathrm{building},\:\mathrm{a}\:\mathrm{man} \\ $$$$\mathrm{observes}\:\mathrm{the}\:\mathrm{top}\:\mathrm{of}\:\mathrm{a}\:\mathrm{tree}\:\mathrm{at}\:\mathrm{an}\:\mathrm{angle}\:\mathrm{of} \\ $$$$\mathrm{depression}\:\mathrm{30}°.\:\mathrm{If}\:\mathrm{the}\:\mathrm{tree}\:\mathrm{is}\:\mathrm{50}\:\mathrm{m}\:\mathrm{tall},\:\mathrm{the} \\ $$$$\mathrm{angle}\:\mathrm{of}\:\mathrm{depression}\:\mathrm{of}\:\mathrm{the}\:\mathrm{foot}\:\mathrm{of}\:\mathrm{the}\:\mathrm{tree}\:\mathrm{is} \\ $$$$\mathrm{viewed}\:\mathrm{by}\:\mathrm{the}\:\mathrm{man}\:\mathrm{is}\:? \\ $$ Answered by sandy_suhendra…

An-aeroplane-leaves-a-port-P-51-S-29-E-and-after-flying-7597-km-due-north-it-reached-another-port-R-calculate-the-i-Latitude-of-R-correct-to-the-nearest-degree-ii-Radius-of-parallel-of-latit

Question Number 10227 by Tawakalitu ayo mi last updated on 30/Jan/17 $$\mathrm{An}\:\mathrm{aeroplane}\:\mathrm{leaves}\:\mathrm{a}\:\mathrm{port}\:\mathrm{P}\left(\mathrm{51}°\mathrm{S},\:\:\mathrm{29}°\mathrm{E}\right)\:\mathrm{and} \\ $$$$\mathrm{after}\:\mathrm{flying}\:\mathrm{7597}\:\mathrm{km}\:\mathrm{due}\:\mathrm{north}\:\mathrm{it}\:\mathrm{reached}\: \\ $$$$\mathrm{another}\:\mathrm{port}\:\mathrm{R}.\:\mathrm{calculate}\:\mathrm{the}. \\ $$$$\left(\mathrm{i}\right)\:\mathrm{Latitude}\:\mathrm{of}\:\mathrm{R}\:\mathrm{correct}\:\mathrm{to}\:\mathrm{the}\:\mathrm{nearest}\:\mathrm{degree} \\ $$$$\left(\mathrm{ii}\right)\:\mathrm{Radius}\:\mathrm{of}\:\mathrm{parallel}\:\mathrm{of}\:\mathrm{latitude}\:\mathrm{through}\:\mathrm{R} \\ $$$$\mathrm{to}\:\mathrm{the}\:\mathrm{nearest}\:\mathrm{whole}\:\mathrm{number}. \\ $$ Answered…

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Question Number 10155 by Tawakalitu ayo mi last updated on 27/Jan/17 $$\mathrm{solve}\:\mathrm{for}\:\mathrm{x} \\ $$$$\mathrm{sin}\left(\mathrm{x}\right)\:−\:\sqrt{\mathrm{3cos}\left(\mathrm{x}\right)}\:=\:\mathrm{1} \\ $$ Answered by mrW1 last updated on 28/Jan/17 $$\mathrm{sin}\:\left({x}\right)=\mathrm{1}+\sqrt{\mathrm{3cos}\:\left({x}\right)}\geqslant\mathrm{1} \\…