Question

Suppose that the functions r and s are defined for all real numbers x as follows. r(x) = 4x ^ 2 s(x) = 2xWrite the expressions for (s + r)(x) and (sr)(x) and evaluate (s - r)(- 1)

Answer 1

You have the following expressions:

$\begin{gathered} r(x)=4x^2 \\ s(x)=2x \end{gathered}$

For the required operations between the previous functions, you obtain:

$(s+r)(x)=s(x)+r(x)=4x^2+2x$

The result is 4x^2 + 2x

$(s*r)(x)=s(x)r(x)=4x^2*2x=8x^3$

The result is 8x^3

$\begin{gathered} (s-r)(-1)=s(-1)-r(-1) \\ (s-r)(-1)=4(-1)^2-2(-1)=4+2=6 \end{gathered}$

The result is 6