00:01
So for this question, let's draw those curves first.
00:07
So here is xxy axis.
00:12
And the first function, y equals x minus 2 squared.
00:18
So it's actually y equal to x squared shift to the right by 2.
00:23
So here is 2, and the function will just look like x squared.
00:34
Okay, and y equal to x is a line, a straight line.
00:43
So this is our y equals to x, and the first line is y equal to x square.
00:54
Okay, so our area are enclosed regions here.
01:05
Alright, so since everything is represented by x, we will integrate with respect to x.
01:12
And to draw a typical approximating rectangle, so say we draw a rectangle right here, and we zoom out this rectangle, so this will be our typical approximating rectangle, it's a rectangle, right? so the wealth will be delta x, and the height, the height will be the upper curve minus the lower curve.
01:44
So the upper curve is xi, and our lower curve here is x i square so x i minus x i square then we can write down our formula for the area of this region area of this region a will equals to integral with respect to x and we need to find the boundary for x we can see from the picture the boundary start from here x1 here x2 right so we know our integral goes from x1 to x2 and we'll figure out those x1 and x2s later and the integral we put in is just this height here it's x i minus x i square so when we put here it's just x minus x squared now let's try to find x1 and x2 so we know x1 x2 are just the intersection for those two curves so we put them to so which means our x i should satisfy both equations in other words x i if we put into the oh sorry i made a mistake here this is x minus 2 to the square so actually here is so here is x minus 2 squared right so the height will be x x i minus x i minus 2 squared and here we change it to x minus 2 squared right and to find those x1 and x2 we plug into the equation so we basically we got x i minus 2 squared equals to x i in other words the typical approximating rectangle at x1 and x2 the height will be 0 right as you can see that the shrink down to no height here is just a dot in fact it's just a dot so there's no height in other words, this equal to 0.
04:55
So this will give us this formula right there.
04:58
Then we can solve for x1 and x2.
05:01
X1 is the smaller one and x2 is a bigger one.
05:05
So let's do that...