Menu Close

Category: Algebra

If-1-a-2-1-b-2-1-c-2-1-ab-1-bc-1-ca-then-prove-that-a-b-c-

Question Number 70312 by Shamim last updated on 03/Oct/19 $$\mathrm{If},\:\frac{\mathrm{1}}{\mathrm{a}^{\mathrm{2}} }+\frac{\mathrm{1}}{\mathrm{b}^{\mathrm{2}} }+\frac{\mathrm{1}}{\mathrm{c}^{\mathrm{2}} }\:=\:\frac{\mathrm{1}}{\mathrm{ab}}+\frac{\mathrm{1}}{\mathrm{bc}}+\frac{\mathrm{1}}{\mathrm{ca}}\:\mathrm{then}\:\mathrm{prove}\: \\ $$$$\mathrm{that},\:\mathrm{a}=\mathrm{b}=\mathrm{c}. \\ $$ Commented by MJS last updated on 03/Oct/19 $$\mathrm{this}\:\mathrm{is}\:\mathrm{true}\:\mathrm{for}\:{a},\:{b},\:{c}\:\in\mathbb{R}…

Let-be-a-binary-operation-on-Z-defined-by-x-y-1-2-x-y-1-1-2-1-1-x-y-Is-associative-

Question Number 4775 by Yozzii last updated on 08/Mar/16 $${Let}\:\ast\:{be}\:{a}\:{binary}\:{operation}\:{on}\:\mathbb{Z} \\ $$$${defined}\:{by}\: \\ $$$${x}\ast{y}=\frac{\mathrm{1}}{\mathrm{2}}\left({x}+{y}+\mathrm{1}+\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{1}+\left(−\mathrm{1}\right)^{{x}+{y}} \right)\right). \\ $$$${Is}\:\ast\:{associative}? \\ $$ Commented by prakash jain last updated…

Find-all-real-a-such-that-f-x-ax-sinx-is-periodic-u-is-the-fractional-part-function-of-the-real-number-u-

Question Number 4748 by Yozzii last updated on 04/Mar/16 $${Find}\:{all}\:{real}\:\boldsymbol{{a}}\:{such}\:{that}\: \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:{f}\left({x}\right)=\left\{\boldsymbol{{a}}{x}+{sinx}\right\}\: \\ $$$${is}\:{periodic}.\:\left\{{u}\right\}\:{is}\:{the}\:{fractional}−{part} \\ $$$${function}\:{of}\:{the}\:{real}\:{number}\:{u}. \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

Prove-that-a-1-a-2-a-n-n-a-1-2-a-2-2-a-n-2-n-with-equality-holding-iff-a-1-a-2-a-n-

Question Number 4719 by prakash jain last updated on 29/Feb/16 $$\mathrm{Prove}\:\mathrm{that} \\ $$$$\frac{{a}_{\mathrm{1}} +{a}_{\mathrm{2}} +…+{a}_{{n}} }{{n}}\leqslant\sqrt{\frac{{a}_{\mathrm{1}} ^{\mathrm{2}} +{a}_{\mathrm{2}} ^{\mathrm{2}} +…+{a}_{{n}} ^{\mathrm{2}} }{{n}}} \\ $$$$\mathrm{with}\:\mathrm{equality}\:\mathrm{holding}\:\mathrm{iff}\:{a}_{\mathrm{1}} ={a}_{\mathrm{2}}…

Prove-or-counterexample-that-if-a-finite-number-of-terms-of-a-series-are-given-then-a-infinite-number-of-formulas-for-n-th-term-exists-which-satisfy-the-given-finite-number-of-terms-For-example-3

Question Number 4720 by prakash jain last updated on 29/Feb/16 $$\mathrm{Prove}\:\mathrm{or}\:\mathrm{counterexample}\:\mathrm{that}\:\mathrm{if}\:\mathrm{a}\:\mathrm{finite}\:\mathrm{number}\: \\ $$$$\mathrm{of}\:\mathrm{terms}\:\mathrm{of}\:\mathrm{a}\:\mathrm{series}\:\mathrm{are}\:\mathrm{given}\:\mathrm{then}\:\mathrm{a}\:\mathrm{infinite}\:\mathrm{number} \\ $$$$\mathrm{of}\:\mathrm{formulas}\:\mathrm{for}\:{n}^{{th}} \:\mathrm{term}\:\mathrm{exists}\:\mathrm{which}\:\mathrm{satisfy} \\ $$$$\mathrm{the}\:\mathrm{given}\:\mathrm{finite}\:\mathrm{number}\:\mathrm{of}\:\mathrm{terms}. \\ $$$$\mathrm{For}\:\mathrm{example} \\ $$$$\mathrm{33},\mathrm{9},\mathrm{33},\mathrm{44},? \\ $$$$\mathrm{4}\:\mathrm{terms}\:\mathrm{are}\:\mathrm{given}\:\mathrm{if}\:{a}_{{n}} ={f}\left({n}\right)\:\mathrm{then}\:\mathrm{there}\:\mathrm{are}…

Question-135786

Question Number 135786 by JulioCesar last updated on 16/Mar/21 Commented by Ar Brandon last updated on 16/Mar/21 $$\mathrm{You}\:\mathrm{mean}\: \\ $$$$\mathrm{H}=\underset{\mathrm{n}\rightarrow\infty} {\mathrm{lim}}\frac{\mathrm{1}+\frac{\mathrm{1}}{\mathrm{2}}+\frac{\mathrm{1}}{\mathrm{4}}+\centerdot\centerdot\centerdot+\frac{\mathrm{1}}{\mathrm{2}^{\mathrm{n}} }}{\mathrm{1}+\frac{\mathrm{1}}{\mathrm{3}}+\frac{\mathrm{1}}{\mathrm{9}}+\centerdot\centerdot\centerdot+\frac{\mathrm{1}}{\mathrm{3}^{\mathrm{n}} }}\:??? \\ $$…