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Category: Set Theory

Question-69568

Question Number 69568 by Ajao yinka last updated on 25/Sep/19 Commented by mathmax by abdo last updated on 25/Sep/19 $$\:{if}\:{n}=\mathrm{1}\:\:\:\:\:\:{H}\:={C}\:\:\:\:\:{if}\:{n}\neq\mathrm{1}\:\:{we}\:{have}\:{z}={z}^{{n}} \:\Leftrightarrow\:{z}^{{n}−\mathrm{1}} =\mathrm{1}\:\:\:{let}\:{z}\:={r}\:{e}^{{i}\theta} \:\:{so} \\ $$$${z}^{{n}−\mathrm{1}}…

Let-A-denotes-the-Set-of-Algebraic-Numbers-and-T-the-Set-of-Trancedental-Numbers-Discuss-the-following-Are-A-and-T-closed-with-respect-to-addition-and-multiplication-Are-A-0-and-T-clos

Question Number 4027 by Rasheed Soomro last updated on 27/Dec/15 $${Let}\:\mathbb{A}\:{denotes}\:{the}\:{Set}\:{of}\:{Algebraic}\:{Numbers} \\ $$$${and}\:\:\mathbb{T}\:\:\:{the}\:{Set}\:{of}\:{Trancedental}\:{Numbers}. \\ $$$${Discuss}\:{the}\:{following}: \\ $$$$\bullet{Are}\:\mathbb{A}\:{and}\:\mathbb{T}\:\:\boldsymbol{{closed}}\:{with}\:{respect}\:{to}\:\: \\ $$$$\boldsymbol{{addition}}\:{and}\:\boldsymbol{{multiplication}}\:? \\ $$$$\bullet{Are}\:\mathbb{A}−\left\{\mathrm{0}\right)\:\:{and}\:\mathbb{T}\:\:\boldsymbol{{closed}}\:{with}\:{respect}\:{to}\:\: \\ $$$$\boldsymbol{{division}}? \\ $$…

Prove-that-P-set-of-prime-numbers-is-countable-

Question Number 3551 by prakash jain last updated on 15/Dec/15 $$\mathrm{Prove}\:\mathrm{that}\:\mathbb{P}\:\mathrm{set}\:\mathrm{of}\:\mathrm{prime}\:\mathrm{numbers}\:\mathrm{is} \\ $$$$\mathrm{countable}. \\ $$ Commented by Filup last updated on 15/Dec/15 $$\mathrm{ah},\:\mathrm{i}\:\mathrm{understand}\:\mathrm{the}\:\mathrm{question}\:\mathrm{now}. \\ $$$$\mathrm{I}\:\mathrm{can}'\mathrm{t}\:\mathrm{answer}\:\mathrm{it},\:\mathrm{though}…

If-A-B-C-and-D-are-any-four-sets-then-i-A-B-C-D-A-C-B-D-ii-A-B-C-D-A-C-B-D-

Question Number 3130 by Rasheed Soomro last updated on 05/Dec/15 $${If}\:{A},{B},{C}\:{and}\:{D}\:{are}\:{any}\:{four}\:{sets}\:{then} \\ $$$$\left({i}\right)\:\:\left({A}−{B}\right)\cup\left({C}−{D}\right)\overset{?} {=}\left({A}\cup{C}\right)−\left({B}\cup{D}\right) \\ $$$$\left({ii}\right)\:\left({A}−{B}\right)\cup\left({C}−{D}\right)\overset{?} {=}\left({A}\cup{C}\right)−\left({B}\cap{D}\right) \\ $$ Answered by prakash jain last updated…

Prove-the-set-1-2-3-1989-can-be-expressed-as-the-disjoint-union-of-A-1-A-2-A-117-such-that-i-each-A-i-contains-the-same-number-of-elements-and-ii-the-sum-of-all-elements-of-each-A

Question Number 133419 by liberty last updated on 22/Feb/21 $$\mathrm{Prove}\:\mathrm{the}\:\mathrm{set}\:\left\{\mathrm{1},\mathrm{2},\mathrm{3},…,\mathrm{1989}\right\} \\ $$$$\mathrm{can}\:\mathrm{be}\:\mathrm{expressed}\:\mathrm{as}\:\mathrm{the}\:\mathrm{disjoint} \\ $$$$\mathrm{union}\:\mathrm{of}\:\mathrm{A}_{\mathrm{1}} ,\mathrm{A}_{\mathrm{2}} ,…,\mathrm{A}_{\mathrm{117}} \:\mathrm{such}\:\mathrm{that} \\ $$$$\left(\mathrm{i}\right)\:\mathrm{each}\:\mathrm{A}_{\mathrm{i}} \:\mathrm{contains}\:\mathrm{the}\:\mathrm{same}\:\mathrm{number}\:\mathrm{of}\:\mathrm{elements}\:,\mathrm{and} \\ $$$$\left(\mathrm{ii}\right)\:\mathrm{the}\:\mathrm{sum}\:\mathrm{of}\:\mathrm{all}\:\mathrm{elements}\:\mathrm{of}\:\mathrm{each}\:\mathrm{A}_{\mathrm{i}} \:\mathrm{is} \\ $$$$\mathrm{the}\:\mathrm{same}\:\mathrm{for}\:\mathrm{i}=\mathrm{1},\mathrm{2},\mathrm{3},…,\mathrm{m}…

Given-that-Z-0-1-2-all-integers-0-R-0-0-01-1-1-01-all-reals-0-Prove-that-R-gt-Z-

Question Number 1875 by Filup last updated on 20/Oct/15 $$\mathrm{Given}\:\mathrm{that}: \\ $$$${Z}=\left\{\mathrm{0},\:\mathrm{1},\:\mathrm{2},\:…\right\}\:\mathrm{all}\:\mathrm{integers}\:\geqslant\mathrm{0} \\ $$$${R}=\left\{\mathrm{0},\:\mathrm{0}.\mathrm{01},\:…,\:\mathrm{1},\:\mathrm{1}.\mathrm{01},\:…\right\}\:\mathrm{all}\:\mathrm{reals}\:\geqslant\mathrm{0} \\ $$$$\:\mathrm{Prove}\:\mathrm{that}\:\mid{R}\mid>\mid{Z}\mid \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

If-A-and-B-are-two-sets-and-U-is-a-universal-set-prove-that-A-B-B-A-A-B-

Question Number 1744 by Rasheed Ahmad last updated on 13/Sep/15 $${If}\:\boldsymbol{\mathrm{A}}\:{and}\:\boldsymbol{\mathrm{B}}\:{are}\:{two}\:{sets}\:{and}\:\mathbb{U}\:{is} \\ $$$${a}\:{universal}\:{set}\:{prove}\:{that} \\ $$$$\boldsymbol{\mathrm{A}}\:\subseteq\:\boldsymbol{\mathrm{B}}\:\:\Rightarrow\:\boldsymbol{\mathrm{B}}=\boldsymbol{\mathrm{A}}\:\cup\:\left(\boldsymbol{\mathrm{A}}'\:\cap\:\boldsymbol{\mathrm{B}}\right) \\ $$ Answered by Rasheed Ahmad last updated on 19/Sep/15…

Are-A-B-A-B-and-A-B-completely-equivalent-Simplify-A-B-A-B-to-A-B-using-set-operations-and-their-properties-

Question Number 1698 by Rasheed Ahmad last updated on 01/Sep/15 $$\bullet{Are}\:\boldsymbol{\mathrm{A}}\cup\boldsymbol{\mathrm{B}}=\boldsymbol{\mathrm{A}}\cap\boldsymbol{\mathrm{B}}\:\:{and}\:\:\boldsymbol{\mathrm{A}}=\boldsymbol{\mathrm{B}}\: \\ $$$${completely}\:{equivalent}? \\ $$$$\bullet{Simplify}\:\boldsymbol{\mathrm{A}}\cup\boldsymbol{\mathrm{B}}=\boldsymbol{\mathrm{A}}\cap\boldsymbol{\mathrm{B}}\:{to}\:\boldsymbol{\mathrm{A}}=\boldsymbol{\mathrm{B}} \\ $$$${using}\:{set}\:{operations}\:{and}\:{their} \\ $$$${properties}. \\ $$ Answered by 123456 last…