00:01
So in this question, we're asked to find the local and global maxima and minima for the function f of x equals x to the third minus e to the x.
00:11
And below, on the left hand side, i plotted some points.
00:15
I plotted negative 1, f of negative 1, and 5 f of 5.
00:21
Because these are the end points of our graph.
00:24
Our domain given is negative 1 is less than or equal to x is less than or equal to 5.
00:30
So in this region, i'm going to plot the endpoints in blue and green respectively, the lower end point and the higher end point.
00:40
Okay, so in this graph, we have some special points.
00:44
We have these endpoints, and we also have some minima, some extrama.
00:48
We have, from left to right, we'll start with this blue point, negative 1, negative 1 .37, let's say.
01:00
This is a local minimum because in a vicinity around this point, depending on your instructor's definition, this is a local minimum because in a neighborhood around this point, it is the lowest point on the interval.
01:17
Because we're only talking about for this interval, x values greater than negative one.
01:25
So by definition, this is the lowest point that it can achieve on that interval, negative 1 to some very small interval around negative 1.
01:36
So that makes it a local extrama and therefore a local minimum because it's the lowest point...