Question

My teacher said that when you are finding the slope of a line. That you can use any two points. So i used two points that were next to each other and got an answer and then i did two more points and got a different answer that wasnt as exact. The first time i got -3/4.4 ,but the second time with the other points i got 1/2. Am i doing something wrong?

Answer 1

please help!

Answer 2

Are you measuring the locations of the points accurately? And are both points on the same line?

Answer 3

-3/4.4 and 1/2 are very different slopes. There may have been an error in calculation or in keeping your x's and y's consistent.

Answer 4

Well for the first one its not on an exact line so the measurment isnt exact. Its in between two numbers. Should i go with the two points that seem like they are right? Because when i check them on the graph included i can see that it is not exact i tried entering it in as rise/run.

Answer 5

If you don't have the exact coordinates (or at least a precise measurement), then you can't get an accurate slope. A the very least, though, the two slopes you calculate should have the same sign and not be more than 5-10% different from one another.

Can you tell me what four points you used?

Answer 6

yeah... (3,2) with (5,3)
and.. (2,1.4) with (3,2)

Answer 7

Ok, assuming (3,2) and (5,3) are exact coordinates, then (2,1.4) is near that line, but not exactly on it. It's close enough that you should get very similar slopes using either pair of lines, though

Answer 8

If (3,2), and (5,3) are definitely on the line, then (2,1.5) is.

Answer 9

Can you show me how you calculated the slope of "-3/4.4? " I think that's where your error is.

Answer 10

sure... okay so