Question

What is the discontinuity of the function f(x) = the quantity of x squared minus 3 x minus 28, all over x plus 4?

Answer 1

Discontinuities can happen when you divide by zero, since that's not allowed right? So how might you find when you'd divide by zero with this? Set the denominator equal to zero and solve away.

Answer 2

I got 0, is that correct?

Answer 3

hold on

Answer 4

wat work did u show

Answer 5

I just set x+4 equal to 0, then I got -4. So I plugged that into the x values and simplified

Answer 6

i beleive so

Answer 7

No, wrong.

Answer 8

Once you've solved for x=-4, you have found the value of x that causes the denominator to be zero. So if you plug in -4 for x, you will get after plugging in to this:

(x^2- 3 x -28)/(x+ 4)

((-4)^2-3(-4)-28)/(-4+4)

So you can see you'll divide by zero, since -4+4=0.

You can simplify this so that it appears to be x-7, but this is actually making it into a different function altogether that no longer has the discontinuity. So they appear to be the same EVERYWHERE EXCEPT at x=-4.

Answer 9

ohhhh okay, I understand it now. thank you so much!!

Answer 10

Glad I could help! =)