first order lnear diff eq
my integrating factor would be x^-2
@johnweldon1993
What kind of linear equation is this? \[y'=P(x)y+Q(x)\quad\text{or}\quad y'+P(x)y=Q(x)~~?\]
I only ask because in your drawing you have two equal signs...
dy/dx + P(x)y = Q(x)
no i mean.. dy/dx- 2y/x = x^2 e^x im sorry
\[\frac{dy}{dx}-\frac{2}{x}y=x^2e^x\] Integrating factor: \[\ln \mu(x)=\int -\frac{2}{x}\,dx~~\implies~~\mu(x)=x^{-2}\] Distributing the IF, you have \[\begin{align*} \frac{1}{x^2}\frac{dy}{dx}-\frac{2}{x^3}y&=e^x\\\\ \frac{d}{dx}\left[\frac{1}{x^2}y\right]&=e^x\\\\ \frac{1}{x^2}y&=\int e^x\,dx\\\\ \frac{1}{x^2}y&=e^x+C\\\\ y&=x^2e^x+Cx^2 \end{align*}\] Knowing that \(y=0\) when \(x=1\), yo can then find a value for \(C\).
c= 2.72
c= -2.72
Right, it's the negative one. Typically, you're better off with the exact form, \(C=-e\).
yezzz thank you so muccch
Join our real-time social learning platform and learn together with your friends!