Question

Which function is an extended function

Answer 1

Answer:

D. The last option

Explanation:

You can't divide by 0, so find out when the given function is discontinuous.

$\frac{x^3+3x^2-x-3}{x^2-1} =\frac{x^3+3x^2-x-3}{(x+1)(x-1)}$

You can see that x is discontinuous at x=-1,1, so find a piecewise function that fill in those gaps.

Plug x=-1,1 into your function to find out what values you need to fill in. But of course it's discontinuous at those points, so plug in a number near x=1 and x=-1. I chose x=-1.1 and x=1.1

$f(-1.1)\frac{(-1.1)^3+3(-1.1)^2-(-1.1)-3}{(-1.1)^-1} = 1.9 \approx 2$

$f(1.1)\frac{(1.1)^3+3(1.1)^2-(1.1)-3}{(1.1)^-1} = 4.1 \approx 4$

so we need to fill in 2 at x=-1, and fill in 4 at x=1