Function Notation - Substitution

Complete the table below, by substituting the given value into the expression and evaluating.

Function Definition	Expression	Substitution	Evaluates to
$\displaystyle f(x) = x + 2$	$\displaystyle f(3)$	$\displaystyle 3 + 2$	$\displaystyle 5$
$\displaystyle g(x) = x - 1$	$\displaystyle g(6)$
$\displaystyle h(x) = 3x$	$\displaystyle h(4)$
$\displaystyle k(x) = 2x - 1$	$\displaystyle k(5)$

Function Definition

Expression

Substitution

Evaluates to

$\displaystyle f(x) = x + 2$

$\displaystyle f(3)$

$\displaystyle 3 + 2$

$\displaystyle 5$

$\displaystyle g(x) = x - 1$

$\displaystyle g(6)$

$\displaystyle h(x) = 3x$

$\displaystyle h(4)$

$\displaystyle k(x) = 2x - 1$

$\displaystyle k(5)$

Now that you understand how to evaluate an expression, let’s get some more practice! The table below includes four different functions. Beneath each of them are a collection of different expressions to evaluate.

$\displaystyle m(x) = -2x + 3$	$\displaystyle n(x) = -x + 7$	$\displaystyle v(x) = 10x - 8$	$\displaystyle w(x) = x^2$
$\displaystyle m(3) =$ $\displaystyle -2(3) + 3$	$\displaystyle n(5) =$	$\displaystyle v(7) =$	$\displaystyle w(-2) =$
$\displaystyle -3$
$\displaystyle m(-4) =$	$\displaystyle n(-2) =$	$\displaystyle v(0) =$	$\displaystyle w(10) =$

$\displaystyle m(0) =$	$\displaystyle n(3.5) =$	$\displaystyle v(-10) =$	$\displaystyle w(0) =$

$\displaystyle m(0.5) =$	$\displaystyle n(0) =$	$\displaystyle v(2.5) =$	$\displaystyle w(1.5) =$

mx = -2x + 3 $\displaystyle m(x) = -2x + 3$

nx = -x + 7 $\displaystyle n(x) = -x + 7$

vx = 10x - 8 $\displaystyle v(x) = 10x - 8$

wx = x^2 $\displaystyle w(x) = x^2$

$\displaystyle m(3) =$ $\displaystyle -2(3) + 3$

$\displaystyle n(5) =$

$\displaystyle v(7) =$

$\displaystyle w(-2) =$

$\displaystyle -3$

$\displaystyle m(-4) =$

$\displaystyle n(-2) =$

$\displaystyle v(0) =$

$\displaystyle w(10) =$

$\displaystyle m(0) =$

$\displaystyle n(3.5) =$

$\displaystyle v(-10) =$

$\displaystyle w(0) =$

$\displaystyle m(0.5) =$

$\displaystyle n(0) =$

$\displaystyle v(2.5) =$

$\displaystyle w(1.5) =$

What do you Notice?

What do you Wonder?

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