# Silly Slope Question

This topic is 5070 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Hi all In the textbook "Quick Calculus - A Self Teaching Guide", the author tells the following about the concept "slope" "The slope is the ratio of the vertical distance to the horizontal distance as we go from one point on the line to another, providing that we take the sign of each line segment as in the equation 'Slope = (y2-y1)/(x2-x1)' ". Do you know what's meant by the sentence " provided that we take the sign of each line segment as in the equation 'Slope = (y2-y1)/(x2-x1)' " ? (the author is dead, so he cannot help me)

##### Share on other sites
He is saying that you want to calculate slope from point x1,y1 to x2,y2 -- which has a sign. In other words, is the "change in x" positive or negative? Is the "change in y" positive or negative? By "change in x" I mean, the change from x1 to x2.

The slope is defined by the "change in y" over the "change in x".

After reading my response it seems somewhat convoluted, but I'll post just in case it sheds a little light on it for you. :)

##### Share on other sites
A math expert confirmed more or less what I was thinking :)

##### Share on other sites
Basically it's just clarifying that slope is positive if y increases with x. Like so:

/

and negative if y decreases as x increases:

\

##### Share on other sites
... it gives a better indication of why slope is the way it is:

Cheers,

Timkin

• 11
• 19
• 12
• 9
• 34
• ### Forum Statistics

• Total Topics
631398
• Total Posts
2999840
×