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Category: Algebra

f-1-f-x-f-x-f-x-

Question Number 1280 by Rasheed Soomro last updated on 19/Jul/15 $$\:{f}\:\left(\:\frac{\mathrm{1}}{{f}\left({x}\right)}\right)={f}\left({x}\right)\: \\ $$$${f}\left({x}\right)=? \\ $$ Commented by 123456 last updated on 19/Jul/15 $${f}\left({x}\right)=\frac{\mathrm{1}}{{x}} \\ $$…

Determine-f-x-when-f-f-x-x-

Question Number 1278 by Rasheed Soomro last updated on 19/Jul/15 $${Determine}\:{f}\left({x}\right)\:{when}\:{f}\left(\:{f}\left({x}\right)\right)={x}\:\:. \\ $$ Commented by prakash jain last updated on 19/Jul/15 $${f}\left({x}\right)=\frac{{ax}+{b}}{{cx}+{d}} \\ $$$${f}\left({f}\left({x}\right)\right)=\frac{{a}\frac{{ax}+{b}}{{cx}+{d}}+{b}}{{c}\frac{{ax}+{b}}{{cx}+{d}}+{d}}={x} \\…

What-is-degree-of-x-y-x-and-y-are-both-variables-Is-x-y-and-a-constant-of-same-degree-

Question Number 1260 by Rasheed Ahmad last updated on 18/Jul/15 $$\mathrm{What}\:\mathrm{is}\:\mathrm{degree}\:\mathrm{of}\:\frac{\mathrm{x}}{\mathrm{y}}\:?\:\left(\mathrm{x}\:\mathrm{and}\:\mathrm{y}\:\mathrm{are}\:\mathrm{both}\:\mathrm{variables}\right) \\ $$$$\mathrm{Is}\:\frac{\mathrm{x}}{\mathrm{y}}\:\:\mathrm{and}\:\mathrm{a}\:\mathrm{constant}\:\mathrm{of}\:\mathrm{same}\:\mathrm{degree}? \\ $$ Commented by prakash jain last updated on 18/Jul/15 $$\mathrm{Degree}\:\mathrm{of}\:\mathrm{rational}\:\mathrm{expression}\:\mathrm{is}\:\mathrm{the}\:\mathrm{degree} \\…

Rasheed-Ahmad-Rasheed-Soomro-For-f-x-where-x-and-f-x-both-are-real-the-x-f-x-can-be-plotted-as-a-point-easily-Now-consider-F-X-where-X-and-F-X-are-complex-numbers-How-can-X-F-X-be-plo

Question Number 1239 by Rasheed Ahmad last updated on 17/Jul/15 $${Rasheed}\:{Ahmad}\:\left({Rasheed}\:{Soomro}\right) \\ $$$$\bullet\mathrm{For}\:\mathrm{f}\left(\mathrm{x}\right)\:\mathrm{where}\:\mathrm{x}\:\mathrm{and}\:\mathrm{f}\left(\mathrm{x}\right)\:\mathrm{both}\:{are} \\ $$$$\mathrm{real}\:\mathrm{the}\:\left(\mathrm{x},{f}\left({x}\right)\right)\:{can}\:{be}\:{plotted}\:{as} \\ $$$${a}\:{point}\:{easily}.\:\bullet{Now}\:{consider}\:{F}\left({X}\right) \\ $$$${where}\:{X}\:{and}\:{F}\left({X}\right)\:{are}\:{complex}\: \\ $$$${numbers}.\:{How}\:{can}\:\left({X},{F}\left({X}\right)\right)\:{be} \\ $$$${plotted}?\:{For}\:{a}\:{particular}\:{example}:\:\left(\mathrm{3}+\mathrm{2}{i},\mathrm{4}−\mathrm{5}{i}\right) \\ $$$${how}\:{can}\:{be}\:{plotted}?…

Question-132295

Question Number 132295 by shaker last updated on 13/Feb/21 Commented by mathmax by abdo last updated on 13/Feb/21 $$\mathrm{f}\left(\mathrm{x}\right)=\mathrm{logx}−\sqrt{\mathrm{5x}−\mathrm{5}}\:\:\:\mathrm{f}\:\mathrm{defined}\:\mathrm{on}\:\left[\mathrm{1},+\infty\left[\right.\right. \\ $$$$\mathrm{f}^{'} \left(\mathrm{x}\right)=\frac{\mathrm{1}}{\mathrm{x}}−\frac{\mathrm{5}}{\mathrm{2}\sqrt{\mathrm{5x}−\mathrm{5}}}\:=\frac{\mathrm{1}}{\mathrm{x}}−\frac{\sqrt{\mathrm{5}}}{\mathrm{2}\sqrt{\mathrm{x}−\mathrm{1}}}\:=\frac{\mathrm{2}\sqrt{\mathrm{x}−\mathrm{1}}−\sqrt{\mathrm{5}}\mathrm{x}}{\mathrm{2x}\sqrt{\mathrm{x}−\mathrm{1}}} \\ $$$$=\frac{\left(\mathrm{2}\sqrt{\mathrm{x}−\mathrm{1}}−\sqrt{\mathrm{5}}\mathrm{x}\right)\left(\mathrm{2}\sqrt{\mathrm{x}−\mathrm{1}}+\sqrt{\mathrm{5}}\mathrm{x}\right)}{\mathrm{2x}\sqrt{\mathrm{x}−\mathrm{1}}\left(\mathrm{2}\sqrt{\mathrm{x}−\mathrm{1}}+\sqrt{\mathrm{5}}\mathrm{x}\right)}\:=\frac{\mathrm{4}\left(\mathrm{x}−\mathrm{1}\right)−\mathrm{5x}^{\mathrm{2}} }{\left(…\right)}=\frac{−\mathrm{5x}^{\mathrm{2}}…