Being able to find a derivative is a "must do" lesson for any student taking Calculus. Derivatives are
found all over science and math, and are a measure of how one variable changes with respect to another variable.
If you are taking your first Calculus class, derviatives are sort of like little "puzzles" that you have to work out. When all of the math, limits, and technical stuff boils away, it leaves behind many rules for how to "take a derivative."
This page can help you to find the derivative of some simple mathematical expressions. It cannot do them all, but you are welcome to try!