Area Functions

$1$a Define $A(x)$ to be the area bounded by the $x-$axis and the function $f(x)=3$ between the $y-$axis and the vertical line at $x.($See the diagram.$)$

$A(1)=$

$A(2)=$

$A(3)=$

$A(4)=$

$$ and, in general,

$A(x)=,(a$ formula $)$