Derivative of a constant function

To understand the meaning of a derivative is not easy, but to know how to take derivatives is not difficult. The best way of learning it is, obviously, through practice.

The following table contains a few functions $f(x)$ in the first column and its derivatives $f '(x)$ in the second one. Look at it and try to complete it:

$f (x)$ $f'(x)$
$1$ $0$
$5$ $0$
$230$ $0$
$0,76$ $0$
$A$ $0$
$N$ ?
$3B$ ?

Solution:$$\begin{array} {ll} f(x)=N & f'(x)=0 \\ f(x)=3B & f'(x)=0\end{array}$$

Note that in all the cases the derivative is zero. The derivative of a constant function is zero, irrespective of the constant. In the last examples, you have seen that $f (x) =A$, $f (x) =N$ and $f (x) =3B$. In all of them the parameter that is changing, $x$, does not appear, thus the derivative will always be zero.

Practice exercises