0:00:00.690,0:00:04.360 In the last video, we started to explore[br]the notion of an error function. 0:00:04.360,0:00:06.120 Not to be confused with the expected value 0:00:06.120,0:00:08.000 because it really does reflect the same[br]notation. 0:00:08.000,0:00:09.810 But here E is for error. 0:00:09.810,0:00:10.840 And we could also thought it will 0:00:10.840,0:00:13.180 some times here referred to as Reminder[br]function. 0:00:13.180,0:00:16.750 And we saw it's really just the difference[br]as we, 0:00:16.750,0:00:20.440 the difference between the function and[br]our approximation of the function. 0:00:20.440,0:00:25.980 So for example, this, this distance right[br]over here, that is our error. 0:00:25.980,0:00:29.680 That is our error at the x is equal to b. 0:00:29.680,0:00:32.340 And what we really care about is the[br]absolute value of it. 0:00:32.340,0:00:35.290 Because at some points f of x might be[br]larger than the polynomial. 0:00:35.290,0:00:37.500 Sometimes the polynomial might be larger[br]than f of x. 0:00:37.500,0:00:40.860 What we care is the absolute distance[br]between them. 0:00:40.860,0:00:42.500 And so what I want to do in this video is 0:00:42.500,0:00:48.430 try to bound, try to bound our error at[br]some b. 0:00:48.430,0:00:49.560 Try to bound our error. 0:00:49.560,0:00:52.640 So say it's less than or equal to some[br]constant value. 0:00:52.640,0:00:55.840 Try to bound it at b for some b is greater[br]than a. 0:00:55.840,0:00:58.070 We're just going to assume that b is[br]greater than a. 0:00:58.070,0:01:01.620 And we saw some tantalizing, we, we got to[br]a bit of a tantalizing 0:01:01.620,0:01:04.519 result that seems like we might be able to[br]bound it in the last video. 0:01:04.519,0:01:07.660 We saw that the n plus 1th derivative of[br]our error 0:01:07.660,0:01:12.060 function is equal to the n plus 1th[br]derivative of our function. 0:01:12.060,0:01:14.760 Or their absolute values would also be[br]equal to. 0:01:14.760,0:01:18.330 So if we could somehow bound the n plus[br]1th derivative 0:01:18.330,0:01:22.240 of our function over some interval, an[br]interval that matters to us. 0:01:22.240,0:01:24.770 An interval that maybe has b in it. 0:01:24.770,0:01:29.980 Then, we can, at least bound the n plus[br]1th derivative our error function. 0:01:29.980,0:01:31.390 And then, maybe we can do a little bit of 0:01:31.390,0:01:36.120 integration to bound the error itself at[br]some value b. 0:01:36.120,0:01:37.160 So, let's see if we can do that. 0:01:37.160,0:01:40.060 Well, let's just assume, let's just assume[br]that we're in a reality where 0:01:40.060,0:01:44.300 we do know something about the n plus1[br]derivative of f of x. 0:01:44.300,0:01:46.420 Let's say we do know that this. 0:01:46.420,0:01:49.150 We do it in a color I that haven't used[br]yet. 0:01:49.150,0:01:50.580 Well, I'll do it in white. 0:01:50.580,0:01:55.400 So let's say that that thing over there[br]looks something like that. 0:01:55.400,0:01:59.420 So that is f the n plus 1th derivative. 0:01:59.420,0:02:00.500 The n plus 1th derivative. 0:02:00.500,0:02:03.740 And I only care about it over this[br]interval right over here. 0:02:03.740,0:02:06.140 Who cares what it does later, I just gotta[br]bound it over the interval 0:02:06.140,0:02:09.759 cuz at the end of the day I just wanna[br]balance b right over there. 0:02:09.759,0:02:12.750 So let's say that the absolute value of[br]this. 0:02:12.750,0:02:13.740 Let's say that we know. 0:02:13.740,0:02:17.350 Let me write it over here, let's say that[br]we know. 0:02:19.170,0:02:23.800 We know that the absolute value of the n[br]plus 1th derivative, the n plus 1th. 0:02:23.800,0:02:26.520 And, I apologize I actually switch between[br]the capital N and 0:02:26.520,0:02:28.120 the lower-case n and I did that in the[br]last video. 0:02:28.120,0:02:29.690 I shouldn't have, but now that you know 0:02:29.690,0:02:32.078 that I did that hopefully it doesn't[br]confuse it. 0:02:32.078,0:02:35.090 N plus 1th, so let's say we know that the[br]n plus 1th 0:02:35.090,0:02:40.110 derivative of f of x, the absolute value[br]of it, let's say it's bounded. 0:02:40.110,0:02:43.010 Let's say it's less than or equal to some[br]m 0:02:43.010,0:02:45.160 over the interval, cuz we only care about[br]the interval. 0:02:45.160,0:02:47.540 It might not be bounded in general, but[br]all we 0:02:47.540,0:02:50.168 care is it takes some maximum value over[br]this interval. 0:02:50.168,0:02:57.190 So over, over, over the interval x, I[br]could write it this way, 0:02:57.190,0:03:04.190 over the interval x is a member between a[br]and b, so this includes both of them. 0:03:04.190,0:03:06.330 It's a closed interval, x could be a, x 0:03:06.330,0:03:09.940 could be b, or x could be anything in[br]between. 0:03:09.940,0:03:11.760 And we can say this generally that, 0:03:11.760,0:03:15.230 that this derivative will have some[br]maximum value. 0:03:15.230,0:03:20.060 So this is its, the absolute value,[br]maximum value, max value, m for max. 0:03:20.060,0:03:23.980 We know that it will have a maximum value,[br]if this thing is continuous. 0:03:23.980,0:03:26.620 So once again we're going to assume that[br]it is continuous, 0:03:26.620,0:03:30.710 that it has some maximum value over this[br]interval right over here. 0:03:30.710,0:03:34.796 Well this thing, this thing right over[br]here, we know is the 0:03:34.796,0:03:38.978 same thing as the n plus 1 derivative of[br]the error function. 0:03:38.978,0:03:46.220 So then we know, so then that, that[br]implies, that implies that, 0:03:46.220,0:03:51.980 that implies that the, that's a new color,[br]let me do that in blue, or that green. 0:03:51.980,0:03:58.720 That implies that the, the, the end plus[br]one derivative of the error function. 0:03:58.720,0:04:00.270 The absolute value of it because these are[br]the 0:04:00.270,0:04:04.570 same thing is also, is also bounded by m. 0:04:04.570,0:04:07.500 So that's a little bit of an interesting[br]result but it gets us no where near there. 0:04:07.500,0:04:11.450 It might look similar but this is the n[br]plus 1 derivative of the error function. 0:04:11.450,0:04:14.000 And, and we'll have to think about how we[br]can get an m in the future. 0:04:14.000,0:04:16.140 We're assuming that we some how know it[br]and maybe 0:04:16.140,0:04:18.589 we'll do some example problems where we[br]figure that out. 0:04:18.589,0:04:20.160 But this is the m plus 1th derivative. 0:04:20.160,0:04:21.750 We bounded it's absolute value but we 0:04:21.750,0:04:24.210 really want to bound the actual error[br]function. 0:04:24.210,0:04:27.710 The 0 is the derivative, you could say,[br]the actual function itself. 0:04:27.710,0:04:31.380 What we could try to integrate both sides[br]of this and see 0:04:31.380,0:04:34.960 if we can eventually get to e, to get to e[br]of x. 0:04:34.960,0:04:38.095 To get our, to our error function or our[br]remainder function so let's do that. 0:04:38.095,0:04:44.050 Let's take the integral, let's take the[br]integral of both sides of this. 0:04:44.050,0:04:46.290 Now the integral on this left hand side,[br]it's a little interesting. 0:04:46.290,0:04:47.930 We take the integral of the absolute[br]value. 0:04:47.930,0:04:51.570 It would be easier if we were taking the[br]absolute value of the integral. 0:04:51.570,0:04:54.220 And lucky for us, the way it's set up. 0:04:54.220,0:04:56.480 So let me just write a little aside here. 0:04:56.480,0:04:59.369 We know generally that if I take, and it's[br]something for you to think about. 0:04:59.369,0:05:03.029 If I take, so if I have two options, if I[br]have two 0:05:03.029,0:05:09.090 options, this option versus and I don't[br]know, they look the same right now. 0:05:10.530,0:05:12.870 I know they look the same right now. 0:05:12.870,0:05:15.810 So over here, I'm gonna have the integral[br]of the absolute value 0:05:15.810,0:05:19.690 and over here I'm going to have the[br]absolute value of the interval. 0:05:19.690,0:05:24.310 Which of these is going to be, which of[br]these can be larger? 0:05:24.310,0:05:26.790 Well, you just have to think about the[br]scenarios. 0:05:26.790,0:05:30.170 So, if f of x is always positive over the[br]interval that 0:05:30.170,0:05:33.470 you're taking the integration, then[br]they're going to be the same thing. 0:05:33.470,0:05:34.990 They're, you're gonna get positive values. 0:05:34.990,0:05:36.760 Take the absolute of a value of a positive[br]value. 0:05:36.760,0:05:38.260 It doesn't make a difference. 0:05:38.260,0:05:40.990 What matters is if f of x is negative. 0:05:40.990,0:05:43.780 If f of x, if f of x is negative the 0:05:43.780,0:05:48.170 entire time, so if this our x-axis, that[br]is our y-axis. 0:05:48.170,0:05:51.070 If f of x is, well we saw if it's positive[br]the entire 0:05:51.070,0:05:55.310 time, you're taking the absolute value of[br]a positive, absolute value of positive. 0:05:55.310,0:05:56.130 It's not going to matter. 0:05:56.130,0:05:57.860 These two things are going to be equal. 0:05:57.860,0:06:00.800 If f of x is negative the whole time, then[br]you're going 0:06:00.800,0:06:04.920 to get, then this integral going to[br]evaluate to a negative value. 0:06:04.920,0:06:07.440 But then, you would take the absolute[br]value of it. 0:06:07.440,0:06:10.090 And then over here, you're just going to,[br]this is, the integral going to 0:06:10.090,0:06:12.820 value to a positive value and it's still[br]going to be the same thing. 0:06:12.820,0:06:15.300 The interesting case is when f of x is[br]both 0:06:15.300,0:06:18.970 positive and negative, so you can imagine[br]a situation like this. 0:06:18.970,0:06:22.580 If f of x looks something like that, then 0:06:22.580,0:06:25.580 this right over here, the integral, you'd[br]have positive. 0:06:25.580,0:06:28.560 This would be positive and then this would[br]be negative right over here. 0:06:28.560,0:06:30.810 And so they would cancel each other out. 0:06:30.810,0:06:32.230 So this would be a smaller value than 0:06:32.230,0:06:35.580 if you took the integral of the absolute[br]value. 0:06:35.580,0:06:39.470 So the integral, the absolute value of f[br]would look something like this. 0:06:39.470,0:06:42.260 So all of the areas are going to be, if[br]you view the 0:06:42.260,0:06:43.120 integral, if you view this it is 0:06:43.120,0:06:44.730 definitely going to be a definite[br]integral. 0:06:44.730,0:06:48.380 All of the areas, all of the areas would[br]be positive. 0:06:48.380,0:06:49.750 So when you it, you are going to get a 0:06:49.750,0:06:53.210 bigger value when you take the integral of[br]an absolute value. 0:06:53.210,0:06:54.791 Then you will, especially when f of x 0:06:54.791,0:06:57.038 goes both positive and negative over the[br]interval. 0:06:57.038,0:07:02.005 Then you would if you took the integral[br]first and then the absolute value. 0:07:02.005,0:07:04.090 Cuz once again, if you took the integral[br]first, for something like 0:07:04.090,0:07:07.020 this, you'd get a low value cause this[br]stuff would cancel out. 0:07:07.020,0:07:09.500 Would cancel out with this stuff right[br]over here then you'd 0:07:09.500,0:07:13.470 take the absolute value of just a lower, a[br]lower magnitude number. 0:07:13.470,0:07:15.880 And so in general, the integral, the 0:07:15.880,0:07:18.260 integral, sorry the absolute value of the[br]integral 0:07:18.260,0:07:22.870 is going to be less than or equal to the[br]integral of the absolute value. 0:07:22.870,0:07:24.670 So we can say, so this right here is the[br]integral of 0:07:24.670,0:07:27.740 the absolute value which is going to be[br]greater than or equal. 0:07:27.740,0:07:29.840 What we have written over here is just[br]this. 0:07:29.840,0:07:31.910 That's going to be greater than or equal[br]to, and I 0:07:31.910,0:07:34.550 think you'll see why I'm why I'm doing[br]this in a second. 0:07:34.550,0:07:39.670 Greater than or equal to the absolute[br]value, the absolute 0:07:39.670,0:07:45.920 value of the integral of, of the n plus[br]1th derivative. 0:07:45.920,0:07:48.960 The n plus 1th derivative of, x, dx. 0:07:48.960,0:07:51.490 And the reason why this is useful, is that[br]we can still 0:07:51.490,0:07:55.090 keep the inequality that, this is less[br]than, or equal to this. 0:07:55.090,0:07:58.700 But now, this is a pretty straight forward[br]integral to evaluate. 0:07:58.700,0:08:00.932 The indo, the anti-derivative of the n[br]plus 0:08:00.932,0:08:04.240 1th derivative, is going to be the nth[br]derivative. 0:08:04.240,0:08:06.510 So this business, right over here. 0:08:06.510,0:08:09.960 Is just going to the absolute value of the[br]nth derivative. 0:08:11.150,0:08:16.310 The absolute value of the nth derivative[br]of our error function. 0:08:16.310,0:08:17.330 Did I say expected value? 0:08:17.330,0:08:17.730 I shouldn't. 0:08:17.730,0:08:18.820 See, it even confuses me. 0:08:18.820,0:08:19.710 This is the error function. 0:08:19.710,0:08:21.900 I should've used r, r for remainder. 0:08:21.900,0:08:22.660 But this all error. 0:08:22.660,0:08:25.170 The, noth, nothing about probability or[br]expected value in this video. 0:08:25.170,0:08:25.850 This is. 0:08:25.850,0:08:27.250 E for error. 0:08:27.250,0:08:30.030 So anyway, this is going to be the nth[br]derivative of our 0:08:30.030,0:08:32.880 error function, which is going to be less[br]than or equal to this. 0:08:32.880,0:08:37.230 Which is less than or equal to the[br]anti-derivative of M. 0:08:37.230,0:08:38.760 Well, that's a constant. 0:08:38.760,0:08:42.630 So that's going to be mx, mx. 0:08:42.630,0:08:44.179 And since we're just taking indefinite[br]integrals. 0:08:44.179,0:08:48.220 We can't forget the idea that we have a[br]constant over here. 0:08:48.220,0:08:49.840 And in general, when you're trying to[br]create an upper 0:08:49.840,0:08:52.220 bound you want as low of an upper bound as[br]possible. 0:08:52.220,0:08:56.640 So we wanna minimize, we wanna minimize[br]what this constant is. 0:08:56.640,0:09:00.180 And lucky for us, we do have, we do know[br]what this, 0:09:00.180,0:09:04.410 what this function, what value this[br]function takes on at a point. 0:09:04.410,0:09:08.430 We know that the nth derivative of our[br]error function at a is equal to 0. 0:09:08.430,0:09:09.940 I think we wrote it over here. 0:09:09.940,0:09:12.480 The nth derivative at a is equal to 0. 0:09:12.480,0:09:15.370 And that's because the nth derivative of[br]the function and the 0:09:15.370,0:09:19.550 approximation at a are going to be the[br]same exact thing. 0:09:19.550,0:09:22.860 And so, if we evaluate both sides of this[br]at a, I'll 0:09:22.860,0:09:27.010 do that over here on the side, we know[br]that the absolute value. 0:09:27.010,0:09:31.560 We know the absolute value of the nth[br]derivative at a, we know 0:09:31.560,0:09:34.670 that this thing is going to be equal to[br]the absolute value of 0. 0:09:34.670,0:09:35.400 Which is 0. 0:09:35.400,0:09:37.820 Which needs to be less than or equal to[br]when you evaluate this 0:09:37.820,0:09:43.420 thing at a, which is less than or equal to[br]m a plus c. 0:09:43.420,0:09:45.260 And so you can, if you look at this part 0:09:45.260,0:09:47.710 of the inequality, you subtract m a from[br]both sides. 0:09:47.710,0:09:51.460 You get negative m a is less than or equal[br]to c. 0:09:51.460,0:09:53.590 So our constant here, based on that little[br]condition 0:09:53.590,0:09:56.310 that we were able to get in the last[br]video. 0:09:56.310,0:10:00.820 Our constant is going to be greater than[br]or equal to negative ma. 0:10:00.820,0:10:03.880 So if we want to minimize the constant, if[br]we wanna get this as low 0:10:03.880,0:10:08.090 of a bound as possible, we would wanna[br]pick c is equal to negative Ma. 0:10:08.090,0:10:10.250 That is the lowest possible c that will 0:10:10.250,0:10:13.170 meet these constraints that we know are[br]true. 0:10:13.170,0:10:16.969 So, we will actually pick c to be negative[br]Ma. 0:10:16.969,0:10:19.364 And then we can rewrite this whole thing[br]as the 0:10:19.364,0:10:22.590 absolute value of the nth derivative of[br]the error function. 0:10:22.590,0:10:24.640 The nth derivative of the error function. 0:10:24.640,0:10:25.970 Not the expected value. 0:10:25.970,0:10:28.010 I have a strange suspicion I might have[br]said expected value. 0:10:28.010,0:10:29.790 But, this is the error function. 0:10:29.790,0:10:30.440 The nth der. 0:10:30.440,0:10:33.230 The absolute value of the nth derivative[br]of the error function 0:10:33.230,0:10:38.600 is less than or equal to M times x minus[br]a. 0:10:38.600,0:10:40.820 And once again all of the constraints[br]hold. 0:10:40.820,0:10:43.880 This is for, this is for x as part of the[br]interval. 0:10:43.880,0:10:48.910 The closed interval between, the closed[br]interval between a and b. 0:10:48.910,0:10:50.220 But looks like we're making progress. 0:10:50.220,0:10:52.910 We at least went from the m plus 1[br]derivative to the n derivative. 0:10:52.910,0:10:55.170 Lets see if we can keep going. 0:10:55.170,0:10:57.750 So same general idea. 0:10:57.750,0:11:00.090 This if we know this then we know that 0:11:00.090,0:11:00.740 we can take the integral of both sides of[br]this. 0:11:00.740,0:11:02.850 So we can take the integral of both sides[br]of this 0:11:06.280,0:11:08.360 the anti derivative of both sides. 0:11:08.360,0:11:10.740 And we know from what we figured out up[br]here 0:11:10.740,0:11:14.780 that something's that's even smaller than[br]this right over here. 0:11:14.780,0:11:19.820 Is, is the absolute value of the integral[br]of the expected value. 0:11:19.820,0:11:21.070 Now [LAUGH] see, I said it. 0:11:21.070,0:11:22.900 Of the error function, not the expected[br]value. 0:11:22.900,0:11:23.900 Of the error function. 0:11:23.900,0:11:27.170 The nth derivative of the error function[br]of x. 0:11:27.170,0:11:29.940 The nth derivative of the error function[br]of x dx. 0:11:29.940,0:11:33.510 So we know that this is less than or equal[br]to based on the exact same logic there. 0:11:33.510,0:11:37.450 And this is useful because this is just[br]going to be, this is just 0:11:37.450,0:11:42.640 going to be the nth minus 1 derivative of[br]our error function of x. 0:11:42.640,0:11:45.160 And of course we have the absolute value[br]outside of it. 0:11:45.160,0:11:46.650 And now this is going to be less than or[br]equal to. 0:11:46.650,0:11:48.390 It's less than or equal to this, which is[br]less than or equal 0:11:48.390,0:11:50.940 to this, which is less than or equal to[br]this right over here. 0:11:50.940,0:11:53.340 The anti-derivative of this right over[br]here is going 0:11:53.340,0:11:58.060 to be M times x minus a squared over 2. 0:11:58.060,0:12:01.410 You could do U substitution if you want or[br]you could just say hey look. 0:12:01.410,0:12:03.820 I have a little expression here, it's[br]derivative is 1. 0:12:03.820,0:12:06.480 So it's implicitly there so I can just[br]treat it as kind of a U. 0:12:06.480,0:12:09.320 So raise it to an exponent and then divide[br]that exponent. 0:12:09.320,0:12:11.460 But once again I'm taking indefinite[br]integrals. 0:12:11.460,0:12:14.350 So I'm going to say a plus C over here. 0:12:14.350,0:12:16.600 But let's use that same exact logic. 0:12:16.600,0:12:19.130 If we evaluate this at A, you're going to[br]have it. 0:12:19.130,0:12:22.250 If you evaluate this while, let's evaluate[br]both sides of this at A. 0:12:22.250,0:12:25.990 the left side, evaluated at A, we know, is[br]going to be zero. 0:12:25.990,0:12:29.250 We figured that out, all, up here in the[br]last video. 0:12:29.250,0:12:31.630 So you get, I'm gonna do it on the right[br]over here. 0:12:31.630,0:12:34.130 You get zero, when you valued the left[br]side of a. 0:12:34.130,0:12:36.820 The right side of a, if you, the right[br]side of the 0:12:36.820,0:12:39.850 value of a you get m times a menus a[br]square over 2. 0:12:39.850,0:12:45.220 So you are gonna get 0 plus c, so you are[br]gonna get, 0 is less or equal to c. 0:12:45.220,0:12:47.620 Once again we want to minimize our constant, 0:12:47.620,0:12:49.800 we wanna minimize our upper boundary up[br]here. 0:12:49.800,0:12:52.930 So we wanna pick the lowest possible c[br]that we talk constrains. 0:12:52.930,0:12:57.440 So the lowest possible c that meets our[br]constraint is zero. 0:12:57.440,0:13:01.070 And so the general idea here is that we[br]can keep doing this, we can 0:13:01.070,0:13:07.270 keep doing exactly what we're doing all[br]the way, all the way, all the way until. 0:13:07.270,0:13:10.440 And so we keep integrating it at the exact[br]same, same way that I've 0:13:10.440,0:13:14.040 done it all the way that we get and using[br]this exact same property here. 0:13:14.040,0:13:19.180 All the way until we get, the bound on the[br]error function of x. 0:13:19.180,0:13:21.550 So you could view this as the 0th[br]derivative. 0:13:21.550,0:13:22.740 You know, we're going all the way to the 0:13:22.740,0:13:25.360 0th derivative, which is really just the[br]error function. 0:13:25.360,0:13:27.620 The bound on the error function of x is[br]going to 0:13:27.620,0:13:29.660 be less than or equal to, and what's it[br]going to be? 0:13:29.660,0:13:31.940 And you can already see the pattern here. 0:13:31.940,0:13:36.270 Is that it's going to be m times x, minus[br]a. 0:13:36.270,0:13:39.490 And the exponent, the one way to think[br]about it, this exponent 0:13:39.490,0:13:42.950 plus this derivative is going to be equal[br]to n plus 1. 0:13:42.950,0:13:46.980 Now this derivative is zero so this[br]exponent is going to be n plus 1. 0:13:46.980,0:13:50.210 And whatever the exponent is, you're going[br]to have,a nd maybe I should 0:13:50.210,0:13:54.280 have done it, you're going to have n plus[br]one factorial over here. 0:13:54.280,0:13:56.950 And if say wait why, where does this n[br]plus 1 factorial come from? 0:13:56.950,0:13:58.370 I just had a two here. 0:13:58.370,0:14:01.120 Well think about what happens when we[br]integrate this again. 0:14:01.120,0:14:04.700 You're going to raise this to the third[br]power and then divide by three. 0:14:04.700,0:14:07.050 So your denominator is going to have two[br]times three. 0:14:07.050,0:14:08.540 Then when you integrate it again, you're[br]going to raise 0:14:08.540,0:14:10.800 it to the fourth power and then divide by[br]four. 0:14:10.800,0:14:12.960 So then your denominator is going to be[br]two times three times four. 0:14:12.960,0:14:14.140 Four factorial. 0:14:14.140,0:14:15.530 So whatever power you're raising to, the 0:14:15.530,0:14:18.500 denominator is going to be that power[br]factorial. 0:14:18.500,0:14:21.240 But what's really interesting now is if we[br]are 0:14:21.240,0:14:24.360 able to figure out that maximum value of[br]our function. 0:14:24.360,0:14:28.510 If we're able to figure out that maximum[br]value of our function right there. 0:14:28.510,0:14:31.800 We now have a way of bounding our error[br]function 0:14:31.800,0:14:36.500 over that interval, over that interval[br]between a and b. 0:14:36.500,0:14:39.530 So for example, the error function at b. 0:14:39.530,0:14:42.040 We can now bound it if we know what an m[br]is. 0:14:42.040,0:14:49.190 We can say the error function at b is[br]going to be less than or equal to m times 0:14:49.190,0:14:57.190 b minus a to the n plus 1th power over n[br]plus 1 factorial. 0:14:57.190,0:15:00.030 So that gets us a really powerful, I guess[br]you 0:15:00.030,0:15:03.720 could call it, result, kinda the, the math[br]behind it. 0:15:03.720,0:15:06.849 And now we can show some examples where[br]this could actually be applied.