Question

A=0 really?
\[y''+9y=e^{3x}\]
\[y_c(x)=c_1cos3x+c_2sin3x\]
\[y_p(x)=Ae^{3x}\]
\[y_p'(x)=3Ae^{3x}\]
\[y_p''(x)=9Ae^{3x}\]
A=0
?
Really?

Answer 1

Hmmm, I'll take a look.

Answer 2

No, A does not equal 0.

Answer 3

hhhmm...let's see where I made a mistake...
Aaaah I seee!!!!
\[9A+9A=1\] (and not =0 hahaha)

Answer 4

There ya' go.

Answer 5

\[y(x)=c_1cos3x+c_2sin3x+\frac1{18}e^{3x}\]