- #1
omar yahia
- 9
- 0
i was trying to get a particular solution of a 3rd order ODE using the variation of parameters method
the homogeneous solution is yh = c1 e-x + c2 ex + c3 e2x
the particular solution is yp=y1u1+y2u2+y3u3
as u1=∫ (w1 g(x) /w) dx , u2=∫ (w2 g(x) /w) dx , u3=∫ (w3 g(x) /w) dx
w =
|y1 y2 y3|
|y'1 y'2 y'3|
|y''1 y''2 y''3|
when i choose y1 , y2 , y3 to be e-x,ex,e2x i get an answer ,
but when i change the arrangement (like: ex,e-x,e2x )
i get another different answer !
so , i have two questions
1 is it normal to have different results when changing who is y1 , y2 , y3 , or am i doing something wrong?
2 if it is normal , does that mean i can have too many different particular solutions , just by changing who is y1 , y2 , y3?
the homogeneous solution is yh = c1 e-x + c2 ex + c3 e2x
the particular solution is yp=y1u1+y2u2+y3u3
as u1=∫ (w1 g(x) /w) dx , u2=∫ (w2 g(x) /w) dx , u3=∫ (w3 g(x) /w) dx
w =
|y1 y2 y3|
|y'1 y'2 y'3|
|y''1 y''2 y''3|
when i choose y1 , y2 , y3 to be e-x,ex,e2x i get an answer ,
but when i change the arrangement (like: ex,e-x,e2x )
i get another different answer !
so , i have two questions
1 is it normal to have different results when changing who is y1 , y2 , y3 , or am i doing something wrong?
2 if it is normal , does that mean i can have too many different particular solutions , just by changing who is y1 , y2 , y3?