# Constructing a differential equation from the solution

## Homework Statement

y = c1e3x+c2xe3x+c3e2xsin(x)+c4e2xcos(x)

## Homework Equations

Differential Equations.

## The Attempt at a Solution

I have the roots of k=3, k=3, k=2+i, k=2-i.
Now I am just stuck on how to put the roots together to get the original equation. I am just stuck on the complex number part.

ehild
Homework Helper
What equation is it which has the roots 3, 3, 2+i and 2-i? How do you get such equation from the differential equation? How the powers of k and the degree of the derivatives are related?

ehild