Gradient

[Yuseph]

Yo guys,

Its chapter 17 now. straight line graph.
Look, at first i thought the formula to get the gradient was (highest y point minus lowest y point) divided by (x point aligned with highest y point minus the other x point). But shortly after i did an exercice where the lowest y point came as the 1st element to be substracted.
At that point it became obvious that it wasnt about highest or lowest. It was about what you consider as being the front of the line.
But its confusing because a graph should.be read from left to right so im not sure why the author would make the gradient a number that indicate a backward evolution.

 

[Deleted member 4993]

Yo guys,

Its chapter 17 now. straight line graph.
Look, at first i thought the formula to get the gradient was (highest y point minus lowest y point) divided by (x point aligned with highest y point minus the other x point). But shortly after i did an exercice where the lowest y point came as the 1st element to be substracted.
At that point it became obvious that it wasnt about highest or lowest. It was about what you consider as being the front of the line.
But its confusing because a graph should.be read from left to right so im not sure why the author would make the gradient a number that indicate a backward evolution.

Look at it carefully - it is from Left to Right.

Suppose two points you chose are L(eft) & R(ight) - then:

gradient = m = \(\displaystyle \frac{\Delta y}{\Delta x} = \frac{y_L - y_R}{x_L - x_R}\) = (y_L - y_R)/(x_L - x_R)

 

[Yuseph]

Look at it carefully - it is from Left to Right.

Suppose two points you chose are L(eft) & R(ight) - then:

gradient = m = \(\displaystyle \frac{\Delta y}{\Delta x} = \frac{y_L - y_R}{x_L - x_R}\) = (y_L - y_R)/(x_L - x_R)

Thanks.
But in exercice 11 its right y minus left y divided by right x minus left x. And in exercice its just like you said when it should be -9 - (-5) / 1 - 0 = -4 / 1 = -4. Ok its the same result but which way is the cleanest and most standard. Left y first or right y first ??

 

[Deleted member 4993]

Thanks.
But in exercice 11 its right y minus left y divided by right x minus left x. And in exercice its just like you said when it should be -9 - (-5) / 1 - 0 = -4 / 1 = -4. Ok its the same result but which way is the cleanest and most standard. Left y first or right y first ??

Most intuitive is - in the "direction of increasing x". But as you found out - it really does not matter as long as you are consistent (at least within a given expression).