Menu Close

Author: Tinku Tara

cos-x-cos-3x-cos-5x-cos-7x-x-

Question Number 147810 by mathdanisur last updated on 23/Jul/21 $$\boldsymbol{{cos}}\left(\boldsymbol{{x}}\right)\:\centerdot\:\boldsymbol{{cos}}\left(\mathrm{3}\boldsymbol{{x}}\right)=\boldsymbol{{cos}}\left(\mathrm{5}\boldsymbol{{x}}\right)\:\centerdot\:\boldsymbol{{cos}}\left(\mathrm{7}\boldsymbol{{x}}\right) \\ $$$$\boldsymbol{{x}}\:=\:? \\ $$ Answered by gsk2684 last updated on 23/Jul/21 $$\mathrm{2}\:\mathrm{cos}\:{x}\:\mathrm{cos}\:\mathrm{3}{x}\:=\:\mathrm{2}\:\mathrm{cos}\:\mathrm{5}{x}\:\mathrm{cos}\:\mathrm{7}{x} \\ $$$$\mathrm{cos}\:\left(\mathrm{3}{x}+{x}\right)+\mathrm{cos}\:\left(\mathrm{3}{x}−{x}\right)=\mathrm{cos}\:\left(\mathrm{7}{x}+\mathrm{5}{x}\right)+\mathrm{cos}\:\left(\mathrm{7}{x}−\mathrm{5}{x}\right) \\…

The-side-lengths-of-an-equiangular-octagon-are-rational-numbers-Prove-that-the-octagon-has-a-symmetry-center-

Question Number 16736 by Tinkutara last updated on 26/Jun/17 $$\mathrm{The}\:\mathrm{side}\:\mathrm{lengths}\:\mathrm{of}\:\mathrm{an}\:\mathrm{equiangular} \\ $$$$\mathrm{octagon}\:\mathrm{are}\:\mathrm{rational}\:\mathrm{numbers}.\:\mathrm{Prove} \\ $$$$\mathrm{that}\:\mathrm{the}\:\mathrm{octagon}\:\mathrm{has}\:\mathrm{a}\:\mathrm{symmetry} \\ $$$$\mathrm{center}. \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

Let-a-1-a-2-a-n-be-the-side-lengths-of-an-equiangular-polygon-Prove-that-if-a-1-a-2-a-n-then-the-polygon-is-regular-

Question Number 16735 by Tinkutara last updated on 26/Jun/17 $$\mathrm{Let}\:{a}_{\mathrm{1}} ,\:{a}_{\mathrm{2}} ,\:…,\:{a}_{{n}} \:\mathrm{be}\:\mathrm{the}\:\mathrm{side}\:\mathrm{lengths}\:\mathrm{of}\: \\ $$$$\mathrm{an}\:\mathrm{equiangular}\:\mathrm{polygon}.\:\mathrm{Prove}\:\mathrm{that}\:\mathrm{if} \\ $$$${a}_{\mathrm{1}} \:\geqslant\:{a}_{\mathrm{2}} \:\geqslant\:…\:\geqslant\:{a}_{{n}} ,\:\mathrm{then}\:\mathrm{the}\:\mathrm{polygon}\:\mathrm{is} \\ $$$$\mathrm{regular}. \\ $$ Terms…

An-equiangular-polygon-with-an-odd-number-of-sides-is-inscribed-in-a-circle-Prove-that-the-polygon-is-regular-

Question Number 16734 by Tinkutara last updated on 26/Jun/17 $$\mathrm{An}\:\mathrm{equiangular}\:\mathrm{polygon}\:\mathrm{with}\:\mathrm{an}\:\mathrm{odd} \\ $$$$\mathrm{number}\:\mathrm{of}\:\mathrm{sides}\:\mathrm{is}\:\mathrm{inscribed}\:\mathrm{in}\:\mathrm{a}\:\mathrm{circle}. \\ $$$$\mathrm{Prove}\:\mathrm{that}\:\mathrm{the}\:\mathrm{polygon}\:\mathrm{is}\:\mathrm{regular}. \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

Question-147800

Question Number 147800 by 0731619 last updated on 23/Jul/21 Answered by Olaf_Thorendsen last updated on 23/Jul/21 $$\mathbb{R}\:=\:\underset{{n}\in\mathbb{Z}} {\cup}\mathrm{E}_{{n}} ,\:\mathrm{E}_{{n}} \:=\:\left[{n},{n}+\mathrm{1}\left[\right.\right. \\ $$$$\forall{x}\in\mathrm{E}_{{n}} ,\:\left\{{x}\right\}\:=\:{x}−\lfloor{x}\rfloor\:=\:{x}−{n} \\ $$$$\forall{x}\in\mathrm{E}_{{n}}…

Solve-2-x-48-16x-

Question Number 16723 by tawa tawa last updated on 25/Jun/17 $$\mathrm{Solve}:\:\mathrm{2}^{\mathrm{x}} \:+\:\mathrm{48}\:=\:\mathrm{16x} \\ $$ Answered by mrW1 last updated on 26/Jun/17 $$\mathrm{2}^{\mathrm{x}} =\mathrm{16}\left(\mathrm{x}−\mathrm{3}\right) \\ $$$$\frac{\mathrm{2}^{\mathrm{x}}…