Need help w/ linear differential equations...
If:
L1=D+1, L2=D-2X^2 ; where D is your differential operator. What is L1L2 and L2L1?

Question

anonymous · Answer

what is L1 & L2...?

anonymous · Answer

function,operator...?

anonymous · Answer

Its in the question, D is the differential operator.

anonymous · Answer

if I'm reading it correctly...:
L1L2=(D+1)*(D-2x^2)=D^2 -D(2x^2) +D(1) - 2x^2=D^2 -4x -2x^2

anonymous · Answer

The answer for L1L2 is: D^2+(D-2x)D-2x(x+2)

anonymous · Answer

I just don't understand how they got that..

anonymous · Answer

me too... looking at that now... may be light will come up..:) give me a min

anonymous · Answer

o.k thanks.

anonymous · Answer

what they are asking is to show that L1L2 does not equal L2L1.

anonymous · Answer

can't get it...
I see D^2 + (D-2x)D... but where is -2x(x+2) comes from?

anonymous · Answer

yeah, thats what I thought...

anonymous · Answer

I dont know if they are doing some product rule....

anonymous · Answer

L2L1 is D^2+(1-2X)D-2x^2

anonymous · Answer

I'll play with it... let you know

anonymous · Answer

thanks.

anonymous · Answer

still getting L1L2=L2L1...
did you try internet?

anonymous · Answer

yeah. I dont think that they are just multiplying them together