00:01
Okay, so this question gives us a equation.
00:05
E in a function of n equals two thirds n minus 1 over 90 n squared, where e equals the effectiveness on a scale from 0 to 10, and n equals the number of times viewers watch a given commercial.
00:18
So we need to figure out what is the most effective number of times if you should watch a commercial to get the highest effectiveness.
00:27
Highest effectiveness.
00:29
So to do that, we're going to need to find a maximum value of this equation here.
00:33
So the way i'm going to find the maximum value of the equation here is i'm going to first find the corresponding n or number of times to watch the commercial so that we get the maximum effectiveness.
00:51
And i'll do that using a formula minus b over to a.
00:55
The minus b here is minus two thirds all over minus two over 90.
01:06
Okay.
01:10
So i'm just going to type that straight into my calculator.
01:13
There's no point getting into the nitty gritty of it, i suppose...