Differential equation problem!!!
Favorites|Homepage
Subscriptions | sitemap
HOME > Mathematics > Differential equation problem!!!

Differential equation problem!!!

[From: ] [author: ] [Date: 11-05-17] [Hit: ]
f(x, y) = ∫ e^x cos(y) + 2y dy = e^x sin(y) + y² + g(x).∂f/∂x = e^x sin(y) = e^x sin(y) + g (x)==> g(x) = 0.e^x sin(y) + y² = C.You cant back y out of this equation,x = ln[(C - y²) csc(y)].......
Solve this initial following

[(e^x cosy+2y)/siny]dy/dx + e^x = 0

-
The equation gives and exact differential form.

(e^x cos(y) + 2y) dy + e^x sin(y) dx = 0.

∂/∂y e^x sin(y) = e^x cos(y) = ∂/∂x (e^x cos(y) + 2y).

So all solutions are defined implicitly by f(x,y) = C where

∂f/∂x = e^x sin(y) and ∂f/∂y = e^x cos(y) + 2y.

Integrate the latter with respect to y.

f(x, y) = ∫ e^x cos(y) + 2y dy = e^x sin(y) + y² + g(x).

Then taking the partial with respect to x

∂f/∂x = e^x sin(y) = e^x sin(y) + g '(x) ==> g'(x) = 0.

So the solutions are defined by

e^x sin(y) + y² = C.

You can't back y out of this equation, but you could express x as a function of y by

x = ln[(C - y²) csc(y)].
1
keywords: equation,Differential,problem,Differential equation problem!!!
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .