Let $f(x) = x^3 - 10 x$. Calculate the difference quotient
$\frac{f(2+h)-f(2)}{h}$ for
$h=.1$
$h=.01$
$h=-.01$
$h=-.1$
If someone now told you that the derivative (slope of the tangent line to the graph) of $f(x)$ at $x=2$ was an integer, what would you expect it to be?