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Category: Trigonometry

If-in-a-ABC-cos-A-cos-B-cos-C-3-2-Prove-that-ABC-is-an-equilateral-triangle-

Question Number 15824 by Tinkutara last updated on 18/Jun/17 $$\mathrm{If}\:\mathrm{in}\:\mathrm{a}\:\Delta{ABC},\:\mathrm{cos}\:{A}\:+\:\mathrm{cos}\:{B}\:+\:\mathrm{cos}\:{C}\:=\:\frac{\mathrm{3}}{\mathrm{2}}\:. \\ $$$$\mathrm{Prove}\:\mathrm{that}\:\Delta{ABC}\:\mathrm{is}\:\mathrm{an}\:\mathrm{equilateral} \\ $$$$\mathrm{triangle}. \\ $$ Answered by mrW1 last updated on 14/Jun/17 $$\mathrm{C}=\mathrm{180}−\left(\mathrm{A}+\mathrm{B}\right) \\…

given-y-sin-pi-3-2x-2cos-pi-12-x-1-where-x-0-2pi-has-maximum-and-minimum-value-is-p-and-q-find-p-2-q-2-A-18-B-16-C-63-4-D-16-

Question Number 81354 by jagoll last updated on 12/Feb/20 $$\mathrm{given}\:\mathrm{y}\:=\:\mathrm{sin}\:\left(\frac{\pi}{\mathrm{3}}−\mathrm{2x}\right)+\mathrm{2cos}\:\left(\frac{\pi}{\mathrm{12}}+\mathrm{x}\right)+\mathrm{1} \\ $$$$\mathrm{where}\:\mathrm{x}\:\in\left(\mathrm{0},\mathrm{2}\pi\right)\:\mathrm{has}\:\mathrm{maximum}\:\mathrm{and} \\ $$$$\mathrm{minimum}\:\mathrm{value}\:\mathrm{is}\:\mathrm{p}\:\mathrm{and}\:\mathrm{q}. \\ $$$$\mathrm{find}\:\mathrm{p}^{\mathrm{2}} −\mathrm{q}^{\mathrm{2}} \:? \\ $$$$\left(\mathrm{A}\right)\:−\mathrm{18}\:\:\:\:\:\:\:\:\:\:\left(\mathrm{B}\right)\:−\mathrm{16} \\ $$$$\left(\mathrm{C}\right)\:\frac{\mathrm{63}}{\mathrm{4}}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\left(\mathrm{D}\right)\:\mathrm{16} \\ $$ Commented…

if-the-sides-a-b-c-of-a-triangle-ABC-are-in-A-P-and-if-sin-A-sin-B-sin-C-cos-sin-B-sin-C-sin-A-cos-sin-C-sin-A-sin-B-cos-then-find-the-value-of-tan-2-2-tan-2-2-

Question Number 146877 by gsk2684 last updated on 16/Jul/21 $${if}\:{the}\:{sides}\:{a},{b},{c}\:{of}\:{a}\:{triangle}\:{ABC} \\ $$$${are}\:{in}\:{A}.{P}.\:{and}\:{if}\: \\ $$$$\mathrm{sin}\:{A}\:=\left(\mathrm{sin}\:{B}\:+\mathrm{sin}\:{C}\right)\mathrm{cos}\:\alpha \\ $$$$\mathrm{sin}\:{B}\:=\left(\mathrm{sin}\:{C}+\mathrm{sin}\:{A}\right)\mathrm{cos}\:\beta \\ $$$$\mathrm{sin}\:{C}\:=\left(\mathrm{sin}\:{A}\:+\mathrm{sin}\:{B}\right)\mathrm{cos}\:\gamma \\ $$$${then}\:{find}\:{the}\:{value}\:{of} \\ $$$$\:\mathrm{tan}\:^{\mathrm{2}} \frac{\alpha}{\mathrm{2}}+\mathrm{tan}\:^{\mathrm{2}} \frac{\gamma}{\mathrm{2}} \\…

if-the-maximum-value-of-4sin-2-x-3cos-2-x-sin-x-2-cos-x-2-3-is-a-b-then-find-a-b-

Question Number 146876 by gsk2684 last updated on 16/Jul/21 $${if}\:{the}\:{maximum}\:{value}\:{of}\: \\ $$$$\mathrm{4sin}\:^{\mathrm{2}} {x}+\mathrm{3cos}\:^{\mathrm{2}} {x}+\mathrm{sin}\:\frac{{x}}{\mathrm{2}}+\mathrm{cos}\:\frac{{x}}{\mathrm{2}}+\mathrm{3} \\ $$$${is}\:{a}+\sqrt{{b}}\:{then}\:{find}\:{a}+{b} \\ $$ Answered by liberty last updated on 16/Jul/21…

In-a-triangle-ABC-if-sin-A-5-x-sin-B-3x-1-sin-C-2x-5-then-find-integral-solutions-x-

Question Number 146875 by gsk2684 last updated on 16/Jul/21 $${In}\:{a}\:{triangle}\:{ABC},\:{if}\: \\ $$$$\frac{\mathrm{sin}\:{A}}{\mathrm{5}−{x}}=\frac{\mathrm{sin}\:{B}}{\mathrm{3}{x}−\mathrm{1}}=\frac{\mathrm{sin}\:{C}}{\mathrm{2}{x}+\mathrm{5}}\:{then}\:{find} \\ $$$$\:{integral}\:{solutions}\:{x}? \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

let-the-line-joining-through-orthocenter-and-circumcenter-of-a-triangle-ABC-is-parallel-to-the-base-BC-then-find-tan-B-tan-C-

Question Number 146874 by gsk2684 last updated on 16/Jul/21 $${let}\:{the}\:{line}\:{joining}\:{through}\: \\ $$$${orthocenter}\:{and}\:{circumcenter}\: \\ $$$${of}\:{a}\:{triangle}\:{ABC}\:{is}\:{parallel}\:{to}\: \\ $$$${the}\:{base}\:{BC}\:{then}\:{find}\:\:\mathrm{tan}\:{B}.\mathrm{tan}\:{C} \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

if-tan-2-x-sec-x-a-1-has-at-least-one-solution-then-find-the-complete-set-of-values-of-a-

Question Number 146868 by gsk2684 last updated on 16/Jul/21 $${if}\:\mathrm{tan}\:^{\mathrm{2}} {x}+\mathrm{sec}\:{x}={a}+\mathrm{1}\:{has}\:{at}\:{least}\: \\ $$$${one}\:{solution}\:{then}\:{find}\:{the}\:{complete}\:{set} \\ $$$${of}\:{values}\:{of}\:\:'{a}'? \\ $$ Answered by Olaf_Thorendsen last updated on 16/Jul/21 $$\mathrm{tan}^{\mathrm{2}}…

Solve-for-x-cos-x-7-cos-2x-7-cos-3x-7-1-2-

Question Number 15786 by tawa tawa last updated on 13/Jun/17 $$\mathrm{Solve}\:\mathrm{for}\:\mathrm{x} \\ $$$$\mathrm{cos}\left(\frac{\mathrm{x}}{\mathrm{7}}\right)\:−\:\mathrm{cos}\left(\frac{\mathrm{2x}}{\mathrm{7}}\right)\:+\:\mathrm{cos}\left(\frac{\mathrm{3x}}{\mathrm{7}}\right)\:=\:\frac{\mathrm{1}}{\mathrm{2}} \\ $$ Commented by tawa tawa last updated on 14/Jun/17 $$\mathrm{please}\:\mathrm{help}\:\mathrm{with}\:\mathrm{this}. \\…