CPM Homework Help : APCALC Problem 5-82

FUNCTIONS FROM TABLES, Part One

Write the equation of the function that fits the points in the table shown below. What kind of function is it?

$x$	$f \left(x\right)$
$0$	$1$
$1$	$5$
$2$	$9$
$3$	$13$
. . .	. . .

Hint:

Compare the finite differences (the between consecutive values of $f\left(x\right)$ ). Are they increasing, decreasing or constant?
What type of graph fits their pattern?