Question

Find the slope for (3,4) and (3,-4)

Answer 1

undefined

The problem:

Find the slope for the line going through (3,4) and (3,-4).

Explanation:

Line up points vertically and subtract.

Then put 2nd difference over 1st.

( 3 , 4)

-(3 , -4)

------------

0 8

So the slope would have been 8/0 but this is undefined.

So the slope is undefined.

Also notice the x's are the same and the y's are difference so this is a vertical line. There is only rise in a vertical line and no run. Recall, slope is rise/run. You cannot divide by 0 so this is why we say the slope is undefined when the x's are always the same no matter the y.