Question and Answers Forum

All Questions      Topic List

Integration Questions

Previous in All Question      Next in All Question      

Previous in Integration      Next in Integration      

Question Number 45352 by Meritguide1234 last updated on 12/Oct/18

Answered by tanmay.chaudhury50@gmail.com last updated on 12/Oct/18

x−y=(x^2 /y^2 )  y((x/y)−1)=(x^2 /y^2 )       t=(x/y)  y(t−1)=t^2   (x/t)(t−1)=t^2   x=(t^3 /(t−1))     y=(x/t)=(t^2 /(t−1))  dx=(((t−1)(3t^2 )−t^3 (1))/((t−1)^2 ))dt  dx=((3t^3 −3t^2 −t^3 )/((t−1)^2 ))dt  ∫(dx/(3y−2x))  =∫(((2t^3 −3t^2 ))/((t−1)^2 (((3t^2 )/(t−1))−((2t^3 )/(t−1)))))dt  ∫(((t−1)(2t^3 −3t^2 ))/((t−1)^2 ×−(2t^3 −3t^2 )))dt  =−1∫(dt/(t−1))  =−ln(t−1)+c  =−ln((x/y)−1)+c  =−ln(x−y)+lny+c  =ln((y/(x−y)))+c   pls check...

$${x}−{y}=\frac{{x}^{\mathrm{2}} }{{y}^{\mathrm{2}} } \\ $$$${y}\left(\frac{{x}}{{y}}−\mathrm{1}\right)=\frac{{x}^{\mathrm{2}} }{{y}^{\mathrm{2}} }\:\:\:\:\:\:\:{t}=\frac{{x}}{{y}} \\ $$$${y}\left({t}−\mathrm{1}\right)={t}^{\mathrm{2}} \\ $$$$\frac{{x}}{{t}}\left({t}−\mathrm{1}\right)={t}^{\mathrm{2}} \\ $$$${x}=\frac{{t}^{\mathrm{3}} }{{t}−\mathrm{1}}\:\:\:\:\:{y}=\frac{{x}}{{t}}=\frac{{t}^{\mathrm{2}} }{{t}−\mathrm{1}} \\ $$$${dx}=\frac{\left({t}−\mathrm{1}\right)\left(\mathrm{3}{t}^{\mathrm{2}} \right)−{t}^{\mathrm{3}} \left(\mathrm{1}\right)}{\left({t}−\mathrm{1}\right)^{\mathrm{2}} }{dt} \\ $$$${dx}=\frac{\mathrm{3}{t}^{\mathrm{3}} −\mathrm{3}{t}^{\mathrm{2}} −{t}^{\mathrm{3}} }{\left({t}−\mathrm{1}\right)^{\mathrm{2}} }{dt} \\ $$$$\int\frac{{dx}}{\mathrm{3}{y}−\mathrm{2}{x}} \\ $$$$=\int\frac{\left(\mathrm{2}{t}^{\mathrm{3}} −\mathrm{3}{t}^{\mathrm{2}} \right)}{\left({t}−\mathrm{1}\right)^{\mathrm{2}} \left(\frac{\mathrm{3}{t}^{\mathrm{2}} }{{t}−\mathrm{1}}−\frac{\mathrm{2}{t}^{\mathrm{3}} }{{t}−\mathrm{1}}\right)}{dt} \\ $$$$\int\frac{\left({t}−\mathrm{1}\right)\left(\mathrm{2}{t}^{\mathrm{3}} −\mathrm{3}{t}^{\mathrm{2}} \right)}{\left({t}−\mathrm{1}\right)^{\mathrm{2}} ×−\left(\mathrm{2}{t}^{\mathrm{3}} −\mathrm{3}{t}^{\mathrm{2}} \right)}{dt} \\ $$$$=−\mathrm{1}\int\frac{{dt}}{{t}−\mathrm{1}} \\ $$$$=−{ln}\left({t}−\mathrm{1}\right)+{c} \\ $$$$=−{ln}\left(\frac{{x}}{{y}}−\mathrm{1}\right)+{c} \\ $$$$=−{ln}\left({x}−{y}\right)+{lny}+{c} \\ $$$$={ln}\left(\frac{{y}}{{x}−{y}}\right)+{c}\:\:\:{pls}\:{check}... \\ $$$$ \\ $$$$ \\ $$

Commented by Meritguide1234 last updated on 12/Oct/18

yes correct...my r.h.s should be (x−y) in denominator.

$${yes}\:{correct}...{my}\:{r}.{h}.{s}\:{should}\:{be}\:\left({x}−{y}\right)\:{in}\:{denominator}. \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com