Question Number 141152 by ZiYangLee last updated on 16/May/21 $$\begin{pmatrix}{\mathrm{3}}&{\mathrm{5}}\\{\mathrm{2}}&{\mathrm{4}}\end{pmatrix}\begin{pmatrix}{{x}}\\{{y}}\end{pmatrix}=\begin{pmatrix}{{x}'}\\{{y}'}\end{pmatrix}\:\mathrm{and}\:\begin{pmatrix}{{a}}&{{b}}\\{{c}}&{{d}}\end{pmatrix}\begin{pmatrix}{{x}'}\\{{y}'}\end{pmatrix}=\begin{pmatrix}{{x}}\\{{y}}\end{pmatrix} \\ $$$$\mathrm{are}\:\mathrm{true}\:\mathrm{for}\:\mathrm{any}\:\mathrm{values}\:\mathrm{of}\:{x},{y},{x}',{y}', \\ $$$$\mathrm{find}\:\mathrm{the}\:\mathrm{values}\:\mathrm{of}\:{a},{b},{c},{d}. \\ $$ Answered by iloveisrael last updated on 16/May/21 $$\Rightarrow\begin{pmatrix}{\mathrm{3}\:\:\:\:\mathrm{5}}\\{\mathrm{2}\:\:\:\:\mathrm{4}}\end{pmatrix}\:\begin{pmatrix}{{a}\:\:\:\:{b}}\\{{c}\:\:\:\:{d}}\end{pmatrix}\:\begin{pmatrix}{{x}'}\\{{y}'}\end{pmatrix}\:=\:\begin{pmatrix}{{x}'}\\{{y}'}\end{pmatrix} \\…
Question Number 10082 by konen last updated on 23/Jan/17 $$\frac{\mathrm{x}}{\mathrm{6}}=\frac{\mathrm{y}}{\mathrm{4}}=\frac{\mathrm{z}}{\mathrm{k}}=\mathrm{k} \\ $$$$\mathrm{x}+\mathrm{y}+\mathrm{z}=−\mathrm{25} \\ $$$$\mathrm{k}=? \\ $$ Commented by ridwan balatif last updated on 23/Jan/17 $$\mathrm{x}+\mathrm{y}+\mathrm{z}=−\mathrm{25}…
Question Number 75616 by mr W last updated on 13/Dec/19 $${A}_{\mathrm{1}} =\mathrm{2} \\ $$$${B}_{\mathrm{1}} =\mathrm{1} \\ $$$${A}_{{n}+\mathrm{1}} ={A}_{{n}} −\mathrm{8}{B}_{{n}} \\ $$$${B}_{{n}+\mathrm{1}} ={A}_{{n}} +\mathrm{7}{B}_{{n}} \\ $$$${find}\:{A}_{{n}}…
Question Number 75617 by mathocean1 last updated on 13/Dec/19 $$\left.\mathrm{Demonstrate}\:\mathrm{that}\:\forall\:\mathrm{x}\:\in\right]\mathrm{0};\frac{\pi}{\mathrm{2}}\left[\right. \\ $$$$\mathrm{tanx}=\frac{\mathrm{1}−\mathrm{cos}\left(\mathrm{2x}\right)}{\mathrm{sin}\left(\mathrm{2x}\right)} \\ $$ Commented by mind is power last updated on 13/Dec/19 $$\mathrm{use}\:\mathrm{cos}\left(\mathrm{2x}\right)=\mathrm{1}−\mathrm{2sin}^{\mathrm{2}} \left(\mathrm{x}\right)…
Question Number 141149 by Dan last updated on 16/May/21 $${lim}_{{x}\rightarrow\infty} \underset{{i}=\mathrm{0}} {\overset{{x}−\mathrm{1}} {\sum}}\frac{{x}}{\left({x}+{i}\right)} \\ $$ Answered by mr W last updated on 16/May/21 $$\frac{{x}}{{x}+{x}}<\frac{{x}}{{x}+{i}}<\frac{{x}}{{x}} \\…
Question Number 141148 by Dan last updated on 16/May/21 $$ \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com
Question Number 75615 by aliesam last updated on 13/Dec/19 Terms of Service Privacy Policy Contact: info@tinkutara.com
Question Number 10078 by ridwan balatif last updated on 23/Jan/17 Commented by ridwan balatif last updated on 23/Jan/17 $$\mathrm{x}_{\mathrm{1}} ^{\mathrm{2011}} +\mathrm{x}_{\mathrm{2}} ^{\mathrm{2011}} =\mathrm{A}\:\mathrm{and}\:\mathrm{x}_{\mathrm{1}} ^{\mathrm{2012}} +\mathrm{x}_{\mathrm{2}}…
Question Number 141150 by jlewis last updated on 16/May/21 $$\mathrm{Determine}\:\mathrm{the}\:\mathrm{concentration}\:\mathrm{of}\left[\mathrm{OH}^{−} \right]\: \\ $$$$\mathrm{in}\:\mathrm{0}.\mathrm{4M}\:\mathrm{NH}_{\mathrm{4}} \mathrm{OH}\:\mathrm{solution}\:\mathrm{having}\: \\ $$$$\mathrm{5}.\mathrm{35g}\:\mathrm{NH}_{\mathrm{4}} \mathrm{Cl}\:\mathrm{in}\:\mathrm{a}\:\mathrm{one}\left(\mathrm{1}\right)\:\mathrm{litre}\:\mathrm{solution}. \\ $$$$\left(\mathrm{k}_{\mathrm{b}} =\mathrm{1}.\mathrm{8}×\mathrm{10}^{−\mathrm{5}} ,\mathrm{N}=\mathrm{14},\mathrm{H}=\mathrm{1},\mathrm{Cl}=\mathrm{35}.\mathrm{5}\right) \\ $$$$ \\ $$…
Question Number 10076 by konen last updated on 23/Jan/17 $$\mathrm{3a}=\mathrm{4b}=\mathrm{5c} \\ $$$$\mathrm{2a}+\mathrm{3b}−\mathrm{c}=\mathrm{146} \\ $$$$\Rightarrow\mathrm{c}=? \\ $$ Answered by ridwan balatif last updated on 23/Jan/17 $$\mathrm{3a}=\mathrm{5c}\rightarrow\mathrm{a}=\frac{\mathrm{5}}{\mathrm{3}}\mathrm{c}…