I have to find the particular solution of the following DE.
Here is how I did it.
Then after rationalizing,
Where as the answer given by the book is,
Can you please tell where is my mistake ?
No ... you multiply the numerator as you would with normal binomials (FOIL if that's what you call it)
Simplify, combinining like terms with like terms and eventually you'll get the numerator in the form of a + bi. As pointed out, a will be your real part and bi will be the imaginary.