Hi everyone,

As you work through WeBWorK #9, you may run into a few instances where it is not obvious what guess to make for the particular solution to the nonhomogeneous equation.Â Here are two tips that might help:

### What if the right side has both an exponential and a trig function?

If the right side of your differential equation has form similar to:Â

then your guess should have the form:Â

### What if the right side is a solution to the complementary equation (where the complementary equation has a repeated root)?

If your initial guess:Â is a solution to the complementary equation, we adjust it by multiplying by : .

IfÂ is *also* a solution to the complementary equation (due to a repeated root), adjust it by multiplying by again:Â .

Let me know if you run into other weird things.Â Questions are natural, and welcome!

Prof. Reitz