00:01
For this problem, we are asked to find the critical numbers of f of x equals 3 minus x times e to the power of x minus 3, if any exist, then to find the open intervals on which the function is increasing or decreasing, and to locate all relative extrema.
00:12
Then we are to use a graphing utility to confirm our results.
00:16
So to begin, we want to differentiate our function.
00:19
You'll have to use product rule, though in a rather simple way.
00:23
A derivative of 3 minus x will be simply negative 1.
00:28
So we'll have negative e to the power of of x minus 3, then we'd have plus 3 minus x times the derivative of e to power of x minus 3, which would be e to the power of x minus 3 times the derivative of x minus 3, which would just be 1.
00:42
So we have that this would then be equal to 3, or let me see how exactly to write this.
00:51
Okay, so we have that we can write this overall as being 2 minus x times e to the power of of x minus 3.
01:03
So we can see that this will be equal to 0 when x equals 2.
01:09
If we take a value or f prime of x less than 2, we'll find that that will give us positive values.
01:17
And if we take f prime of x greater than 2, that will give us negative values...