Math Help Forum - View Single Post

superman69 · #5 October 31st, 2009, 09:44 PM

Quote:

Originally Posted by HallsofIvy

You can also do this as a "homogeneous" equation. Write it as $\frac{dy}{dt}= \frac{9t- 8y}{t}= 9- 8\frac{y}{t}$ .

Let $u= \frac{y}{t}$ . Then $y= tu$ so y'= tu'+ u and the equation becomes tu'+ u= 9- 8u and so tu'= 9- 9u, a separable equation.

So now I use the equation tu'= 9- 9u and plug in u' and u?