00:01
All right, so inflection points occur with the second derivative does not exist or is equal to zero.
00:05
So we're going to find the second derivative, but first we're going to find the first one.
00:08
So just consider this is your first function.
00:10
This is your second apply the product rule.
00:12
So 2x times the derivative of e to 3x, which is e to the 3x times 3, and then add e to the 3x times the 3x, which is 2x, and then add e to the 3x, which is 2x, and then you get g prime.
00:23
Or you can pull out of e to the 3x, and you're left with 2 times 3, which is 6x plus 2.
00:29
Now to find g double prime, let this be your first function, that be your second.
00:32
You get e to the 3x times the derivative of this, which is just 6, plus 6x plus 2, times 3, 8 to the 3x.
00:40
Once again, pull out an e to the 3x, and you get g2priam as e to 3x times the 3x times the quantity 6 plus 18x plus 6.
00:49
That's equal to e to 3x times 18x plus 12.
00:55
Now i'll say each one of these equal to 0, because this will exist everywhere.
00:58
8 to 3x actually never equals 0, so there's no solutions there.
01:01
But 8x plus 12 and most certainly equals 0, it actually equals 0, where 18x is equal to negative 12, so x is equal to negative 2 over 3.
01:10
This is a possible inflection point...