Basic "computation" formulas : Next, let's take a quick look at some basic "computation" formulas that will let us to actually compute some derivatives.

Formulas

1)   If f ( x ) = c then f ′ ( x ) = 0         Or        d (c )/ dx = 0

The derivative of a constant is zero.

2)   If f ( x ) = xⁿ  then f ′ ( x ) = nx^{n -1}  OR    d ( xⁿ ) = nx^{n -1} , n is any number.

Sometimes this formula is called the power rule.  Here all we are doing is bringing the original exponent down in front & multiplying and then subtracting one from the original exponent.

Note that to use this formula n has to be a number, it can't be a variable. Also note that the base, the x, has to be a variable, it can't be a number. 

These are the only properties & formulas which we'll give in this section.  Let's calculate some derivatives using these properties.