Question

How do you find slope?
(8,1) and (8, -4)

Answer 1

Slope for a straight line:
\[m=\frac{y_2-y_1}{x_2-x_1}\]

Answer 2

@Me16
Do you know what to do from there?

Answer 3

Yes Thank you

Answer 4

Okay, glad I could help if your confused just ask again :-).

Answer 5

So the slope would be -5 right?

Answer 6

Okay so we have the points:
\[(8, 1) (8, -4)\]
\[m=\frac{1- (-4)}{8-8}\]
\[m = \dfrac{5}{0}\]
So the slope is undetermined since we have a zero.

Answer 7

For an undefined slope you will get zero in the denominator, which you cannot have because you cannot divide by zero.

For a slope equal to zero, you will get a zero in the numerator. Zero divided by any non-zero denominator, will give you a slope of zero.

(I copied this reasoning from mathref, so no credits to me just trying to explain my work :-).)

Answer 8

I understand how the bottom is 0 but I thought it would be -5 because the formula says you put y2 in before y1 which would make it -4 - 1 = -5

Answer 9

If you graph -5 or 5 they will come out to be the same :-).
\[(8,1)~(8, -4)\Rightarrow (x_2-x_1)\Rightarrow(8-8)\]
\[(8,1)~(8, -4)\Rightarrow (y_2-y_1)\Rightarrow(1-(-4))\Rightarrow(-4 - 1)\]
Either way is fine.

Answer 10

So then the answer is 0?

Answer 11

No it is undefined since the zero is in the denominator.
If the zero was in the numerator it would be 0.

Answer 12

Ohh alright I think I understand now

Answer 13

Okay, great don't be afraid to ask any questions :-).