Question

What value is a discontinuity of x squared plus 2 x plus 3, all over x squared minus x minus 12?
A x = -1
B x = -2
C x = -3
D x = -4

Answer 1

@joyraheb help? or are you busy?

Answer 2

The discontinuity will be where the denominator equal to 0, which is not allowed

Answer 3

So just solve x^2-x-12=0 and find those points

Answer 4

how do I solve it ? I am so stupid with this stuff.

Answer 5

This is your function:
f(x) = (x^2 + 2x + 3)/(x^2-x-12)
right?

Answer 6

I thought the answer was C

Answer 7

we are not supposed to have anything divided by 0, so let's find these points which make the denominator equal to 0

Answer 8

x^2-x-12 = 0, that is a quadratic equation, do you know how to find its roots?

Answer 9

A little bit

Answer 10

Was I right about it being C. -3?

Answer 11

there is two points with discontinuity, since we have a quadratic equation. And yes, C is the correct option

Answer 12

the other point of discontinuit is x = 4

Answer 13

Let me tell you how to solve a quadratic equation

Answer 14

yeah that's what I thought because 4 wasn't a choice so it had to be C // but i'll give you a medal thank you so much!

Answer 15

Consider a general quadratic equation of form:
y = a*x^2 + b*x + c

Answer 16

the roots will be:
\[x = \frac{ -b \pm \sqrt{b^2 -4ac} }{ 2a }\]

Answer 17

;)

Answer 18

that's how you solve them?

Answer 19

Yes

Answer 20

for example in your situation
x^2-x-12 = 0
Here a = 1, b = -1 and c = -12
Just plug in the formula and find the two roots