Second order differential equations

[fan_boy17]

Homework Statement

finding the general solution. I would like to know if the 20-e^x will be treated as a sum of a polynomial?

Homework Equations

The Attempt at a Solution

 

[Mark44]

Homework Statement

finding the general solution. I would like to know if the 20-e^x will be treated as a sum of a polynomial?

Homework Equations

The Attempt at a Solution

20 - e^x is not a polynomial. A search on wikipedia will turn up the definition of a polynomial.

 

[HallsofIvy]

It is, of course, the sum of two functions. Did you really mean to say "polynomial"?

You should look for a "particular solution" of the form A+ Be^x.

 

[LCKurtz]

It is, of course, the sum of two functions. Did you really mean to say "polynomial"?

You should look for a "particular solution" of the form A+ Be^x.

That's a typo, Halls meant $A+Be^{2x}$.

 

[fan_boy17]

can anyone help with solving it :(

 

[LCKurtz]

can anyone help with solving it :(

What are you stuck on? Have you solved the associated homogeneous equation for its general solution $y_c$? Have you tried looking for a particular solution of the NH equation of the form $y_p=A + Be^{2x}$ as has been suggested? It is all straightforward. Show us what you have so far.