Question

Consider the function $2y=1+x.$

Determine $f(2{)}^3-f(3{)}^2.$

• A. $1.75$
• B. $-1.75$

Answer 1

The correct option is B $-1.75$

The given function is $2y=1+x.$
$\Rightarrow y=\frac{1+x}{2}$

$y$ is a function of $x\Rightarrow y=f\left(x\right)$

Let's find f(x) at $x=2$ and $x=3.$

$f\left(2\right)=\frac{1+\left(2\right)}{2}=\frac{3}{2}=1.5$
$f\left(3\right)=\frac{1+\left(3\right)}{2}=\frac{4}{2}=2$

$\therefore f(2{)}^3-f(3{)}^2$
$={1.5}^2-2^2$
$=2.25-4$
$=-1.75$