Here is a sampling of the so-called Elementary Functions, and why you need to know about these in order to solve differential equations.
Polynomials
Exponentials
Sines and Cosines
A cool way to relate polynomials, exponentials, and sinusoids with the same DE!!
Based on the previous results about polynomials, exponentials, and sinusoids, we can deduce that they are solutions to a family of differential equations of a very simple type:
If , is an exponential.
If , is a first degree polynomial.
If , is a sinusoid.
This suggests some sort of deep relationship between these three seemingly completely different kinds of functions.