00:02
So we're given a wire that's 10 centimeters long, and we're going to take that wire and we're going to cut it.
00:09
And one side will have a length x.
00:13
And the other piece will be what's left.
00:15
So it'll be 10 centimeters minus the x that we took off.
00:19
So 10 minus x.
00:21
Then we're going to bend this one, the x one into a square and the 10 minus x into a square.
00:26
So we'll call the first square a1.
00:29
And each of its sides, so a square has four equal sides.
00:32
So if we're going to use x to make the circumference, then we know that one side is going to equal to x over 4.
00:41
And furthermore, that the area is going to be one of those sides squared, which is going to be x over 4 squared, which equals x squared over 16.
00:59
So that's going to be the area of the first guy.
01:02
The area of the second guy, well, let's see, he's going to be his side squared, but what is his side? side two is going to be 10 minus x, but again, it has to do all four sides.
01:15
So we're going to have to divide by four.
01:18
So the second area is going to equal 10 minus x over four the quantity squared.
01:30
So that's going to equal, let's see, 10.
01:35
10 minus x squared is 10 times 10 minus 2 times 10 times x plus negative x squared.
01:49
So negative x times negative x is positive x.
01:53
So there you go.
01:55
And that's all over 16.
01:58
So our job was to find a function for the total area, which would be a1 plus a2.
02:08
Fortunately, they both already have the same denominator.
02:10
So let's see, we're going to have x squared plus x squared, right? this x squared plus this x squared.
02:15
So we're going to have a 2x squared...