tag:blogger.com,1999:blog-2106712996078987699.post3859999495726237220..comments2023-05-25T17:36:24.861+08:00Comments on 觀楓日誌: Simple differential equation IForretriohttp://www.blogger.com/profile/18048483702091533151noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-2106712996078987699.post-59373476073940072013-09-26T23:36:23.287+08:002013-09-26T23:36:23.287+08:00Because v's not a constant. Instead it's a...Because v's not a constant. Instead it's a function w.r.t. time t (i.e. v(t))<br />By product rule, (v(t) e^(rt))' = v'(t) e^(rt) + v(t) re^(rt).<br /><br />The idea of integrating factor is basically making up a multiplying factor so that such a 'reversed version of product rule' can happens.<br /><br />Thanks for your question :3Forretriohttps://www.blogger.com/profile/18048483702091533151noreply@blogger.comtag:blogger.com,1999:blog-2106712996078987699.post-50235703776374099102013-09-22T12:29:07.639+08:002013-09-22T12:29:07.639+08:00why in Example 5 ert(dv/dt + vr) = ertg will make...why in Example 5 ert(dv/dt + vr) = ertg will make d(vert)/dt = gert<br />..?<br />I dont get the simplfication..Anonymousnoreply@blogger.com