please help dont understand it
b is iv
Lines give constant gradients
Positive then negative then positive gradients
a is ii
Has two stationary points, places where gradient is zero
d is iii
Three stationary points
c is i
Descriptions of when gradient is positive or negative will do for a second reason for each
This should get you started. Look at graph (b).
The ‘sharp corners’ at say –1 & 1 mean no derivative there.
Between them the slope is negative, but positive other wise.
There is only one graph that can be. Which one?
Look at (a). That graph has negative until say x=-2, positive slope until x=2 then negative again.
What graph matches that description?