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Category: Algebra

If-a-n-is-sum-of-the-all-primitive-n-th-root-of-unity-Does-n-1-a-n-converge-An-n-th-root-of-unity-say-z-is-primitive-if-it-is-not-k-th-root-of-unity-where-k-lt-n-or-z-n-1-and-z

Question Number 3650 by prakash jain last updated on 18/Dec/15 $$\mathrm{If}\:{a}_{{n}} \:\mathrm{is}\:\mathrm{sum}\:\mathrm{of}\:\mathrm{the}\:\mathrm{all}\:\mathrm{primitive}\:{n}^{{th}} \:\mathrm{root}\:\mathrm{of} \\ $$$$\mathrm{unity}. \\ $$$$\mathrm{Does}\:\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}{a}_{{n}} \:\mathrm{converge}? \\ $$$$\mathrm{An}\:{n}^{{th}} \:\mathrm{root}\:\mathrm{of}\:\mathrm{unity},\:\mathrm{say}\:{z},\:\mathrm{is}\:\mathrm{primitive}\:\mathrm{if}\:\mathrm{it}\:\mathrm{is}\:\mathrm{not} \\ $$$${k}^{{th}}…

If-the-G-M-between-two-numbers-a-b-is-G-and-the-two-A-M-s-between-them-are-p-and-q-then-prove-that-G-2-2p-q-2q-p-

Question Number 3617 by Rasheed Soomro last updated on 16/Dec/15 $${If}\:\:{the}\:{G}.{M}.\:{between}\:{two}\:{numbers}\: \\ $$$${a}\:,\:{b}\:\:\:{is}\:\:{G}\:{and}\:{the}\:{two}\:{A}.{M}.'{s}\:{between} \\ $$$${them}\:{are}\:{p}\:\:{and}\:\:{q}\:,\:{then}\:{prove}\:{that} \\ $$$${G}^{\mathrm{2}} =\left(\mathrm{2}{p}−{q}\right)\left(\mathrm{2}{q}−{p}\right). \\ $$ Commented by Yozzii last updated…

x-4-ax-3-bx-2-cx-d-0-let-x-f-t-linear-perhaps-t-4-At-3-Bt-2-Ct-D-0-can-we-have-4AB-A-3-8C-solving-at-most-a-degree-three-polynomial-

Question Number 69143 by ajfour last updated on 20/Sep/19 $${x}^{\mathrm{4}} +{ax}^{\mathrm{3}} +{bx}^{\mathrm{2}} +{cx}+{d}=\mathrm{0} \\ $$$${let}\:\:{x}={f}\left({t}\right)\:\:{linear}\:{perhaps} \\ $$$${t}^{\mathrm{4}} +{At}^{\mathrm{3}} +{Bt}^{\mathrm{2}} +{Ct}+{D}=\mathrm{0} \\ $$$${can}\:{we}\:{have}\:\: \\ $$$$\:\:\:\mathrm{4}{AB}={A}^{\mathrm{3}} +\mathrm{8}{C}\:\:{solving}\:{at}\:{most}…

1-1-4-6-8-10-12-14-16-18-20-22-S-900-

Question Number 134668 by EDWIN88 last updated on 06/Mar/21 $$\mathrm{1}+\mathrm{1}+\mathrm{4}−\mathrm{6}−\mathrm{8}−\mathrm{10}+\mathrm{12}+\mathrm{14}+\mathrm{16}−\mathrm{18}−\mathrm{20}−\mathrm{22}+… \\ $$$$\mathrm{S}_{\mathrm{900}} \:=\:? \\ $$ Answered by benjo_mathlover last updated on 06/Mar/21 $$\Rightarrow\underset{\mathrm{6}} {\underbrace{\mathrm{1}+\mathrm{1}+\mathrm{4}}}\:\underset{−\mathrm{24}} {\underbrace{−\mathrm{6}−\mathrm{8}−\mathrm{10}}}\:\underset{\mathrm{42}}…

Three-point-are-drawn-on-a-straight-number-line-A-B-and-C-Consider-a-quadractic-equation-x-2-ax-b-0-a-Length-of-line-segment-AB-b-Length-of-line-segment-BC-Give-construction-steps-to-identify-a-poin

Question Number 3588 by prakash jain last updated on 16/Dec/15 $$\mathrm{Three}\:\mathrm{point}\:\mathrm{are}\:\mathrm{drawn}\:\mathrm{on}\:\mathrm{a}\:\mathrm{straight} \\ $$$$\mathrm{number}\:\mathrm{line}\:\mathrm{A},\mathrm{B}\:\mathrm{and}\:\mathrm{C}. \\ $$$$\mathrm{Consider}\:\mathrm{a}\:\mathrm{quadractic}\:\mathrm{equation} \\ $$$${x}^{\mathrm{2}} +{ax}+{b}=\mathrm{0} \\ $$$${a}=\mathrm{Length}\:\mathrm{of}\:\mathrm{line}\:\mathrm{segment}\:\mathrm{AB} \\ $$$${b}=\mathrm{Length}\:\mathrm{of}\:\mathrm{line}\:\mathrm{segment}\:\mathrm{BC} \\ $$$$\mathrm{Give}\:\mathrm{construction}\:\mathrm{steps}\:\mathrm{to}\:\mathrm{identify}\:\mathrm{a}\:\mathrm{points} \\…

Define-the-sequence-a-n-by-the-recurrence-equation-a-n-1-pa-n-qa-n-1-n-1-where-p-q-C-0-and-a-0-a-1-C-Find-a-n-in-terms-of-n-

Question Number 3565 by Yozzii last updated on 15/Dec/15 $${Define}\:{the}\:{sequence}\:\left\{{a}_{{n}} \right\}\:{by}\:{the} \\ $$$${recurrence}\:{equation}\: \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:{a}_{{n}+\mathrm{1}} ={pa}_{{n}} +{qa}_{{n}−\mathrm{1}} \:\:\left({n}\geqslant\mathrm{1}\right) \\ $$$${where}\:{p},{q}\in\mathbb{C}−\left\{\mathrm{0}\right\}\:{and}\: \\ $$$${a}_{\mathrm{0}} =\alpha\:,\:{a}_{\mathrm{1}} =\beta\:\: \\…

Test-for-convergence-1-n-10-2-ln-lnn-nlnn-2-n-2-1-n-lnn-p-two-cases-of-p-to-look-at-3-n-2-1-n-n-lnn-4-n-1-10-n-n-2n-1-5-n-1-

Question Number 3564 by Yozzii last updated on 15/Dec/15 $${Test}\:{for}\:{convergence}: \\ $$$$\left(\mathrm{1}\right)\:\underset{{n}=\mathrm{10}} {\overset{\infty} {\sum}}\frac{\mathrm{2}^{\mathrm{ln}\left(\mathrm{ln}{n}\right)} }{{n}\mathrm{ln}{n}} \\ $$$$\left(\mathrm{2}\right)\underset{{n}=\mathrm{2}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{{n}\left(\mathrm{ln}{n}\right)^{\mathrm{p}} }\:\left(\mathrm{two}\:\mathrm{cases}\:\mathrm{of}\:\mathrm{p}\:\mathrm{to}\:\mathrm{look}\:\mathrm{at}\right) \\ $$$$\left(\mathrm{3}\right)\underset{{n}=\mathrm{2}} {\overset{\infty} {\sum}}\frac{\left(−\mathrm{1}\right)^{{n}} \sqrt{{n}}}{\mathrm{ln}{n}}…