Inverse differential operators

1. Mar 2, 2006

hbomb

I need someone to check some homework problems that i've done so far regarding inverse differential operators.

1) 9y"-4y=sinx
yp=-1/13 sinx

2) y"-4y'-12y=x-6
yp=-1/12(x-6)

3) y'''+10y""+25y'=e^x
yp=36

4) y""+8y'=4
yp=1/2 x

5) y"-9y=54
yp=-6

6) y"-y'-12y=e^(4x)
yp=1/7 xe^(4x)

7) y"+25y=6sinx
yp=1/4 sinx

sorry for not converting the equations into the latex form but i'm kinda of in a hurry. thanks

2. Mar 3, 2006

Fermat

Substitute yp into each of your DE's and check that the lhs = the rhs.

3. Mar 3, 2006

HallsofIvy

Staff Emeritus
Surely you can see that this can't be right!