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Category: Arithmetic

If-tangent-line-of-equation-y-x-3-x-at-x-a-crossed-line-y-x-at-b-b-Find-b-in-terms-of-a-

Question Number 19812 by Joel577 last updated on 16/Aug/17 $$\mathrm{If}\:\mathrm{tangent}\:\mathrm{line}\:\mathrm{of}\:\mathrm{equation}\:{y}\:=\:\frac{{x}}{\mathrm{3}\:−\:{x}}\:\mathrm{at}\: \\ $$$${x}\:=\:{a}\:\mathrm{crossed}\:\mathrm{line}\:{y}\:=\:{x}\:\mathrm{at}\:\left({b},{b}\right) \\ $$$$\mathrm{Find}\:{b}\:\mathrm{in}\:\mathrm{terms}\:\mathrm{of}\:{a} \\ $$ Answered by ajfour last updated on 16/Aug/17 $$\mathrm{y}=−\mathrm{1}−\frac{\mathrm{3}}{\mathrm{x}−\mathrm{3}}\:\:\:\:\:\Rightarrow\:\:\frac{\mathrm{dy}}{\mathrm{dx}}=\frac{\mathrm{3}}{\left(\mathrm{x}−\mathrm{3}\right)^{\mathrm{2}} }…

What-is-the-sum-in-base-10-of-all-the-natural-numbers-less-than-64-which-have-exactly-three-ones-in-their-base-2-representation-

Question Number 19704 by Tinkutara last updated on 14/Aug/17 $$\mathrm{What}\:\mathrm{is}\:\mathrm{the}\:\mathrm{sum}\:\left(\mathrm{in}\:\mathrm{base}\:\mathrm{10}\right)\:\mathrm{of}\:\mathrm{all}\:\mathrm{the} \\ $$$$\mathrm{natural}\:\mathrm{numbers}\:\mathrm{less}\:\mathrm{than}\:\mathrm{64}\:\mathrm{which} \\ $$$$\mathrm{have}\:\mathrm{exactly}\:\mathrm{three}\:\mathrm{ones}\:\mathrm{in}\:\mathrm{their}\:\mathrm{base}\:\mathrm{2} \\ $$$$\mathrm{representation}? \\ $$ Answered by mrW1 last updated on 15/Aug/17…

In-an-A-P-the-common-difference-is-2-and-the-largest-term-exceeds-the-middle-term-by-58-Find-the-smallest-term-of-the-A-P-

Question Number 19683 by 786786AM last updated on 14/Aug/17 $$\mathrm{In}\:\mathrm{an}\:\mathrm{A}.\mathrm{P};\:\mathrm{the}\:\mathrm{common}\:\mathrm{difference}\:\mathrm{is}\:−\mathrm{2}\:\mathrm{and}\:\mathrm{the}\:\mathrm{largest}\:\mathrm{term}\:\:\mathrm{exceeds}\:\mathrm{the}\:\mathrm{middle}\:\mathrm{term}\:\mathrm{by}\:\mathrm{58}. \\ $$$$\mathrm{Find}\:\mathrm{the}\:\mathrm{smallest}\:\mathrm{term}\:\mathrm{of}\:\mathrm{the}\:\mathrm{A}.\mathrm{P}. \\ $$ Answered by Rasheed.Sindhi last updated on 15/Aug/17 $$\mathrm{Let}\:\mathrm{m}\:\mathrm{is}\:\mathrm{a}\:\mathrm{middle}\:\mathrm{term} \\ $$$$\mathrm{m}+\mathrm{58}\:\mathrm{is}\:\mathrm{the}\:\mathrm{largest}\:\mathrm{term}. \\…

Serlea-Shows-that-the-sum-of-the-digit-of-100-25-25-is-divisible-by-4-

Question Number 85184 by Serlea last updated on 19/Mar/20 $$\mathrm{Serlea} \\ $$$$\mathrm{Shows}\:\mathrm{that}\:\mathrm{the}\:\mathrm{sum}\:\mathrm{of}\:\mathrm{the}\:\mathrm{digit}\:\mathrm{of} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{100}^{\mathrm{25}} −\mathrm{25} \\ $$$$\mathrm{is}\:\mathrm{divisible}\:\mathrm{by}\:\mathrm{4}. \\ $$ Commented by mr W last updated…

Determine-the-number-of-five-digit-integers-37abc-in-base-10-such-that-each-of-the-numbers-37abc-37bca-and-37cab-is-divisible-by-37-

Question Number 19637 by Tinkutara last updated on 13/Aug/17 $$\mathrm{Determine}\:\mathrm{the}\:\mathrm{number}\:\mathrm{of}\:\mathrm{five}-\mathrm{digit} \\ $$$$\mathrm{integers}\:\left(\mathrm{37}{abc}\right)\:\mathrm{in}\:\mathrm{base}\:\mathrm{10}\:\mathrm{such}\:\mathrm{that} \\ $$$$\mathrm{each}\:\mathrm{of}\:\mathrm{the}\:\mathrm{numbers}\:\left(\mathrm{37}{abc}\right),\:\left(\mathrm{37}{bca}\right) \\ $$$$\mathrm{and}\:\mathrm{37}{cab}\:\mathrm{is}\:\mathrm{divisible}\:\mathrm{by}\:\mathrm{37}. \\ $$ Answered by Rasheed.Sindhi last updated on 14/Aug/17…

Question-150462

Question Number 150462 by Tawa11 last updated on 12/Aug/21 Answered by puissant last updated on 12/Aug/21 $$\mathrm{I}=\underset{\mathrm{n}=\mathrm{0}} {\overset{\infty} {\sum}}\left(−\mathrm{1}\right)^{\mathrm{n}} \mathrm{ln}\left(\frac{\mathrm{2}+\mathrm{3n}}{\mathrm{1}+\mathrm{3n}}\right) \\ $$$$\mathrm{posons}\:\mathrm{U}_{\mathrm{n}} =\left(−\mathrm{1}\right)^{\mathrm{n}} \mathrm{ln}\left(\frac{\mathrm{2}+\mathrm{3n}}{\mathrm{1}+\mathrm{3n}}\right) \\…