Slope of a function
The derivative $f'(x)$ indicates the slope of the tangents of the function $f$ at the point $x$.
To calculate the slope of a position $x$ of the function, simply insert $x$ into the derivative of the function.
Compute the slope of the function $f(x)=x^2$ at $x=1$.Antiderivative: $f(x)=x^2$
$x=1$ insert: $f'(1)=2\cdot1=2$
To find derivative, see derivation rules.