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Category: Relation and Functions

let-A-n-cos-npi-3-sin-npi-3-sin-npi-3-cos-npi-3-1-calculate-A-0-A-1-and-A-2-2-calculate-det-A-n-is-A-n-inversible-3-calculste-A-n-n-4

Question Number 130064 by mathmax by abdo last updated on 22/Jan/21 $$\mathrm{let}\:\mathrm{A}_{\mathrm{n}} =\begin{pmatrix}{\mathrm{cos}\left(\frac{\mathrm{n}\pi}{\mathrm{3}}\right)\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{sin}\left(\frac{\mathrm{n}\pi}{\mathrm{3}}\right)}\\{\mathrm{sin}\left(\frac{\mathrm{n}\pi}{\mathrm{3}}\right)\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{cos}\left(\frac{\mathrm{n}\pi}{\mathrm{3}}\right)}\end{pmatrix} \\ $$$$\left.\mathrm{1}\right)\:\mathrm{calculate}\:\mathrm{A}_{\mathrm{0}} ,\mathrm{A}_{\mathrm{1}} \:\mathrm{and}\:\mathrm{A}_{\mathrm{2}} \\ $$$$\left.\mathrm{2}\right)\:\mathrm{calculate}\:\mathrm{det}\left(\mathrm{A}_{\mathrm{n}} \right)\:\mathrm{is}\:\mathrm{A}_{\mathrm{n}} \mathrm{inversible}? \\ $$$$\left.\mathrm{3}\right)\:\mathrm{calculste}\:\mathrm{A}_{\mathrm{n}} ^{\mathrm{n}} \\…

find-all-functin-f-Z-Z-wich-verify-a-b-Z-2-f-2a-2f-b-f-f-a-b-

Question Number 64443 by mathmax by abdo last updated on 18/Jul/19 $${find}\:{all}\:{functin}\:{f}\:{Z}\rightarrow{Z}\:\:{wich}\:{verify} \\ $$$$\forall\left({a},{b}\right)\in{Z}^{\mathrm{2}} \:\:\:\:\:{f}\left(\mathrm{2}{a}\right)+\mathrm{2}{f}\left({b}\right)\:={f}\left({f}\left({a}+{b}\right)\right) \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

let-m-inff-x-x-a-b-and-M-supf-x-x-a-b-prove-that-b-a-2-a-b-f-x-dx-a-b-dx-f-x-b-a-2-m-M-2-4mM-

Question Number 129873 by Bird last updated on 20/Jan/21 $${let}\:{m}={inff}\left({x}\right)_{{x}\in\left[{a},{b}\right]} \\ $$$${and}\:{M}={supf}\left({x}\right)_{{x}\in\left[{a},{b}\right]} \\ $$$${prove}\:{that}\:\left({b}−{a}\right)^{\mathrm{2}} \leqslant\int_{{a}} ^{{b}} {f}\left({x}\right){dx}.\int_{{a}} ^{{b}} \:\frac{{dx}}{{f}\left({x}\right)} \\ $$$$\leqslant\left({b}−{a}\right)^{\mathrm{2}} ×\frac{\left({m}+{M}\right)^{\mathrm{2}} }{\mathrm{4}{mM}} \\ $$…