Ok don’t worry this is a very easy topic
It falls under “gradients of a straight line”
I’ll try my best to explain the question but u can find plenty of videos online (Fuse School or Cognito) explaining the topic in detail.
Gradient means slope or how steep a line is.
To find the gradient we use the formula
(Change in y) / (change in x)
*Step 1*
Choose any two coordinates (exact) of the line from the graph
For line 1 let’s take
(2,4) (-3,4)
Now from this
the change in y= (4-4) = 0
the change in x = (-3-2) = -5
So the gradient = 0/-5 = 0
*Now this makes sense because a straight horizontal line has no slope and thus has a gradient of zero. So even without all the calculation we can figure this out easily.
Now for line 2 let’s take the coordinates:
(-3,1) (-3,3)
The change in y= (3-1) = 2
The change in x = (-3- -3) = 0
So gradient = 2/0 = “Undefined”
*The gradient of vertical straight line is always undefined (no gradient)*
*The gradient of horizontal straight lines is always 0*
Hope this helped and best of luck for your exams!