Solving a Nonlinear Differential Equation with Variable Coefficients

iamtrojan3
Messages
55
Reaction score
0

Homework Statement


this problem was on my finals and i stared at it for 30 mins straight and still didn't figure it out and now it just bothers me that i don't know how to do the first problem on my final exam.

"find the general solution to the dfq"
xy'+xy= 1-y


Homework Equations




The Attempt at a Solution


i don't think its linear cause if you do the integrating factor the right side is interms of x and y
i don't think its separable... or multiplying by 1/x and subbing v for y/x could help
i don't think its exact? or is it I am not sure
bernouli's formula won't help here.
i don't know its probably something really stupid and easy... thanks for the help!
 
Physics news on Phys.org
The y doesn't have to be on the right side. Write it as x*y'+(x+1)*y=1. Now divide by x and find the integrating factor.
 
OH MY GOD. there goes 20 points that i should of gotten. thank you for the helpe.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top