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Author: Tinku Tara

if-a-b-c-gt-0-and-a-b-c-1-find-min-1-a-9-b-25-c-a-73-b-75-c-105-d-81-e-83-

Question Number 150880 by mathdanisur last updated on 16/Aug/21 $$\mathrm{if}\:\:\mathrm{a};\mathrm{b};\mathrm{c}>\mathrm{0}\:\:\mathrm{and}\:\:\mathrm{a}+\mathrm{b}+\mathrm{c}=\mathrm{1} \\ $$$$\mathrm{find}\:\boldsymbol{\mathrm{min}}\left(\frac{\mathrm{1}}{\mathrm{a}}\:+\:\frac{\mathrm{9}}{\mathrm{b}}\:+\:\frac{\mathrm{25}}{\mathrm{c}}\right)\:=\:? \\ $$$$\left.\mathrm{a}\left.\right)\left.\mathrm{7}\left.\mathrm{3}\left.\:\:\:\mathrm{b}\right)\mathrm{75}\:\:\:\mathrm{c}\right)\mathrm{105}\:\:\:\mathrm{d}\right)\mathrm{81}\:\:\:\mathrm{e}\right)\mathrm{83} \\ $$ Answered by mr W last updated on 16/Aug/21 $${s}=\frac{\mathrm{1}}{{a}}+\frac{\mathrm{9}}{{b}}+\frac{\mathrm{25}}{\mathrm{1}−{a}−{b}}…

prove-that-any-real-root-of-the-equation-x-6n-4x-2n-4-n-N-0-verify-gt-2-1-2n-

Question Number 150883 by mathdanisur last updated on 16/Aug/21 $$\mathrm{prove}\:\mathrm{that}\:\mathrm{any}\:\mathrm{real}\:\mathrm{root}\:\boldsymbol{\alpha}\:\mathrm{of}\:\mathrm{the} \\ $$$$\mathrm{equation}:\:\:\mathrm{x}^{\mathrm{6}\boldsymbol{\mathrm{n}}} \:=\:\mathrm{4x}^{\mathrm{2}\boldsymbol{\mathrm{n}}} \:+\:\mathrm{4}\:;\:\mathrm{n}\in\mathbb{N}-\left\{\mathrm{0}\right\} \\ $$$$\mathrm{verify}:\:\:\mid\boldsymbol{\alpha}\mid\:>\:\sqrt[{\mathrm{2}\boldsymbol{\mathrm{n}}}]{\mathrm{2}} \\ $$ Answered by mindispower last updated on 16/Aug/21…

For-a-natural-number-b-let-N-b-denote-the-number-of-natural-numbers-a-for-which-the-equation-x-2-ax-b-0-has-integer-roots-What-is-the-smallest-value-of-b-for-which-N-b-20-

Question Number 19799 by Tinkutara last updated on 15/Aug/17 $$\mathrm{For}\:\mathrm{a}\:\mathrm{natural}\:\mathrm{number}\:{b},\:\mathrm{let}\:{N}\left({b}\right)\:\mathrm{denote} \\ $$$$\mathrm{the}\:\mathrm{number}\:\mathrm{of}\:\mathrm{natural}\:\mathrm{numbers}\:{a}\:\mathrm{for} \\ $$$$\mathrm{which}\:\mathrm{the}\:\mathrm{equation}\:{x}^{\mathrm{2}} \:+\:{ax}\:+\:{b}\:=\:\mathrm{0}\:\mathrm{has} \\ $$$$\mathrm{integer}\:\mathrm{roots}.\:\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{smallest} \\ $$$$\mathrm{value}\:\mathrm{of}\:{b}\:\mathrm{for}\:\mathrm{which}\:{N}\left({b}\right)\:=\:\mathrm{20}? \\ $$ Commented by dioph last…

Find-all-the-real-solutions-of-cos-x-cos-5-x-cos-7x-3-

Question Number 150871 by liberty last updated on 16/Aug/21 $$\:\mathrm{Find}\:\mathrm{all}\:\mathrm{the}\:\mathrm{real}\:\mathrm{solutions} \\ $$$$\mathrm{of}\:\mathrm{cos}\:\mathrm{x}+\mathrm{cos}\:^{\mathrm{5}} \mathrm{x}+\mathrm{cos}\:\mathrm{7x}=\mathrm{3} \\ $$ Answered by EDWIN88 last updated on 16/Aug/21 $$\:\mathrm{cos}\:\mathrm{7}{x}+\mathrm{cos}\:{x}=\mathrm{2cos}\:\mathrm{4}{x}\:\mathrm{cos}\:\mathrm{3}{x} \\ $$$$\:=\:\mathrm{2}\left(\mathrm{2cos}\:^{\mathrm{2}}…

One-morning-each-member-of-Manjul-s-family-drank-an-8-ounce-mixture-of-coffee-and-milk-The-amounts-of-coffee-and-milk-varied-from-cup-to-cup-but-were-never-zero-Manjul-drank-1-7-th-of-the-total-am

Question Number 19795 by Tinkutara last updated on 15/Aug/17 $$\mathrm{One}\:\mathrm{morning},\:\mathrm{each}\:\mathrm{member}\:\mathrm{of}\:\mathrm{Manjul}'\mathrm{s} \\ $$$$\mathrm{family}\:\mathrm{drank}\:\mathrm{an}\:\mathrm{8}-\mathrm{ounce}\:\mathrm{mixture}\:\mathrm{of} \\ $$$$\mathrm{coffee}\:\mathrm{and}\:\mathrm{milk}.\:\mathrm{The}\:\mathrm{amounts}\:\mathrm{of}\:\mathrm{coffee} \\ $$$$\mathrm{and}\:\mathrm{milk}\:\mathrm{varied}\:\mathrm{from}\:\mathrm{cup}\:\mathrm{to}\:\mathrm{cup},\:\mathrm{but} \\ $$$$\mathrm{were}\:\mathrm{never}\:\mathrm{zero}.\:\mathrm{Manjul}\:\mathrm{drank}\:\mathrm{1}/\mathrm{7}-\mathrm{th} \\ $$$$\mathrm{of}\:\mathrm{the}\:\mathrm{total}\:\mathrm{amount}\:\mathrm{of}\:\mathrm{milk}\:\mathrm{and}\:\mathrm{2}/\mathrm{17}-\mathrm{th} \\ $$$$\mathrm{of}\:\mathrm{the}\:\mathrm{total}\:\mathrm{amount}\:\mathrm{of}\:\mathrm{coffee}.\:\mathrm{How} \\ $$$$\mathrm{many}\:\mathrm{people}\:\mathrm{are}\:\mathrm{there}\:\mathrm{in}\:\mathrm{Manjul}'\mathrm{s} \\…