Antiderivatives - By The Organic Chemistry Tutor
Transcript
00:00 | in this video , we're going to talk about how | |
00:02 | to find the anti derivative of a function . So | |
00:05 | what is the anti derivative ? What as the name | |
00:10 | implies ? It is the opposite of differentiation . We | |
00:14 | know the derivative of F of X is F prime | |
00:18 | of X . So the anti derivative or the integral | |
00:22 | of F prime of X is F of X . | |
00:27 | So F of X is the anti derivative of F | |
00:30 | prime of X where F prime of X is the | |
00:33 | derivative of F of X . Now the integral or | |
00:39 | the anti derivative of regular F of X is capital | |
00:45 | F of X . So capital F is the anti | |
00:51 | derivative of lowercase F . And lower case F is | |
00:55 | the anti derivative of F prime of X . So | |
00:58 | hopefully that gives you a good idea of what the | |
01:00 | anti derivative is . So let's say if we have | |
01:08 | the second derivative of a function and we want to | |
01:11 | find the first derivative and we can go we can | |
01:16 | keep going forward in this direction . I just want | |
01:20 | to give you an overview of these different symbols and | |
01:24 | functions . So go into the right , we're looking | |
01:29 | for the anti derivative , going to the left , | |
01:39 | we're looking for the derivative . The process of finding | |
01:47 | the anti derivative is basically integration . The process of | |
01:55 | finding the derivative is differentiation . Hopefully that summarizes everything | |
02:07 | that you need to know about this conceptually . No | |
02:15 | , we said that capital F is the integral of | |
02:19 | F . Of X . Dx . Now you you | |
02:25 | get capital F plus C . You always get the | |
02:27 | a constant integration but we're not gonna worry about that | |
02:30 | here . What I'd like to do right now is | |
02:33 | distinguish what is an indefinite integral versus a definite integral | |
02:43 | . So this here is what is known as an | |
02:47 | indefinite integral . An indefinite integral gives you a function | |
02:54 | typically in terms of X . But it could be | |
02:56 | in terms of some other variable like Y or Z | |
02:58 | . Or something like that . A definite integral doesn't | |
03:03 | give you a function , but it gives you a | |
03:06 | number . So this is a definite integral . The | |
03:15 | result of a definite integral . It's always a number | |
03:17 | like 20-845 or something . And you can easily identify | |
03:21 | or distinguish a definite integral from an indefinite integral . | |
03:26 | A definite integral have limits of integration , it has | |
03:29 | a lower limit and the upper limit an indefinite integral | |
03:35 | does not have the limits of integration . So that's | |
03:39 | how you can easily distinguish between them . Now we | |
03:43 | know that the derivative of X cube is three x | |
03:51 | squared according to the power rule . The derivative of | |
03:56 | a variable race to a constant is the constant times | |
04:01 | the variable , erase the constant minus one . Well | |
04:06 | , the anti derivative of a variable race to a | |
04:11 | constant . It's going to be that variable , raising | |
04:14 | the constant plus one Divided by the constant plus one | |
04:19 | and then plus see the constant of integration . So | |
04:24 | that's how we could find the anti derivative of a | |
04:27 | variable race to a constant . So let's find the | |
04:32 | anti derivative of three X squared . So let's rewrite | |
04:37 | the constant . Now the variable rates of the constant | |
04:40 | that's X squared . So we're gonna do is we're | |
04:42 | gonna add one to the exponent . So it's gonna | |
04:45 | be two plus one and then we're gonna divide by | |
04:47 | that result . So it becomes three x cubed divided | |
04:51 | by three . And this gives us the original function | |
04:57 | X cube . But we need to add the constant | |
05:00 | of integration plus C . If you were to find | |
05:04 | the derivative of X cubed plus C . X cube | |
05:10 | will become three X squared . The derivative of a | |
05:14 | constant will become zero . So you end up with | |
05:16 | the same thing . So always when you're looking for | |
05:19 | the indefinite integral something or the anti derivative , you | |
05:23 | need to put the constant of integration . The only | |
05:26 | time you don't need to worry about the constant of | |
05:28 | integration is if you're finding the definite integral where you | |
05:31 | get a number besides that , any time you get | |
05:35 | a function add plus C . When you're looking for | |
05:37 | the indefinite integral or the anti derivative . So now | |
05:43 | let's work on some problems , go ahead and find | |
05:48 | the anti derivative of the following functions . Feel free | |
05:56 | to pause the video and work on these examples . | |
06:07 | So for the first one we're just going to add | |
06:10 | one to the exponent four plus one is five . | |
06:13 | And then we're going to divide by the result and | |
06:15 | then add the constant of integration . So it's X | |
06:18 | to the fifth power over five plus C . For | |
06:21 | the next one is going to be X to the | |
06:25 | 8/8 plus c . For the next one is gonna | |
06:29 | be six . And then we're going to add 1-9 | |
06:31 | that becomes 10 , Divide by 10 Plus C . | |
06:35 | Now this one we can reduce 6/10 . If we | |
06:38 | divide both numbers by two , that becomes three of | |
06:40 | the five . So we could say this equals 3/5 | |
06:45 | . Exit a 10 Plus C . For the next | |
06:52 | one It's gonna be eight X to the 4/4 plus | |
06:57 | c . And we know eight divided by four is | |
07:00 | two . So this is two X to the four | |
07:03 | plus C . Sat . You can see it's not | |
07:07 | that difficult to find the anti derivative of function . | |
07:14 | So go ahead and try this one . Find the | |
07:17 | anti derivative of . So let's try it this way | |
07:21 | let's say F of X is X cubed minus four | |
07:28 | X squared plus eight X . What is the anti | |
07:34 | derivative capital F of X of their function . So | |
07:39 | go ahead and find the anti drift F of X | |
07:44 | . To do that . We're going to find the | |
07:45 | indefinite integral of X cubed minus four x squared plus | |
07:51 | attacks . But just to show our work , let's | |
07:55 | do it this way first . So the anti derivative | |
07:59 | is going to be the indefinite integral of F of | |
08:02 | X dx . So that's the formula . And now | |
08:08 | let's replace F of X with xq minus four X | |
08:13 | squared Plus eight X DX . So the anti derivative | |
08:24 | of X cube is going to be X to the | |
08:26 | fore over four . And then for four X squared | |
08:31 | is going to be four X cube over three . | |
08:33 | And then for a tax it's eight X squared over | |
08:35 | two plus C . Now let's rewrite it . So | |
08:40 | we're gonna be right as 1 4th except for -4/3 | |
08:47 | X cube and then 8/2 is four . So we're | |
08:51 | right that has four X squared plus C . So | |
08:54 | this is the anti derivative of the original function . | |
09:04 | Now let's try another problem . So let's say F | |
09:08 | prime of X . That is the first derivative of | |
09:11 | X . I mean the first derivative of F . | |
09:14 | Rather let's say that's equal to eight X cube -6 | |
09:26 | x squared plus four X minus seven . So given | |
09:34 | F prime of X , find the anti derivative F | |
09:38 | of X . Go ahead and try that . So | |
09:51 | , first let's right an expression involving indefinite integral . | |
09:54 | So we can say that F of X is the | |
09:56 | indefinite integral of F prime of X . Dx So | |
10:03 | F of X is the anti derivative of F prime | |
10:05 | of X . So f of X is going to | |
10:11 | be the indefinite integral of eight . X cube -6 | |
10:18 | x squared plus four X minus seven . Feel free | |
10:28 | to pause the video if you want to try this | |
10:38 | . So the anti derivative of X cube is X | |
10:43 | to the 4th over four . For X squared it's | |
10:47 | X Cube over three and for X to the first | |
10:51 | power It's x squared over two . And then if | |
10:55 | you have a constant like seven , all we gotta | |
10:57 | do is added next to it . We'll talk more | |
11:02 | about that shortly and then finally plus the So now | |
11:07 | let's simplify our answer . So the anti derivative is | |
11:11 | going to be eight divided by four is two . | |
11:14 | So we have two X to the fourth , power | |
11:17 | six divided by three is also too four divided by | |
11:20 | two is the same . So this is the anti | |
11:26 | derivative of our original function two X to the fourth | |
11:29 | power minus two X cubed plus two X squared -7 | |
11:35 | X Plus C . So , as you can see | |
11:39 | it's not too difficult to find an anti derivative , | |
11:41 | but there are other things that you need to know | |
11:45 | . Go ahead and find the indefinite integral of these | |
11:50 | expressions . Let's make this as easy . All right | |
12:18 | , so go ahead and try those . So let's | |
12:22 | start with the first one . We want to find | |
12:24 | the indefinite integral of a constant five and we have | |
12:28 | dx in front of it . So we know it's | |
12:31 | going to be five x . But let's see if | |
12:34 | we can get the answer . Using the power role | |
12:36 | five is the same as five . Exit zero . | |
12:40 | Any variable rates to the zero , power is one | |
12:43 | . So excited Zeros one times 5 , Which is | |
12:47 | equivalent to five . Now using the power rule , | |
12:51 | this is going to be five . We're going to | |
12:53 | add on to the exponents and then divide by that | |
12:55 | result . So the end result is that you get | |
12:58 | five X plus C . So whenever you have a | |
13:04 | constant and you wish to integrate that constant , just | |
13:08 | add a variable to it . Now the variable that | |
13:10 | you should add is based on what you see here | |
13:13 | . Either dx Dy , D R or D . | |
13:17 | C . So what is the indefinite integral of 70 | |
13:21 | y . So instead of seven X this is going | |
13:24 | to be seven times Y plus C . So the | |
13:32 | differential dx dy it tells us what invariable we should | |
13:36 | be adding to the constants . The indefinite integral of | |
13:41 | eight D . R . That's going to be eight | |
13:43 | times are plus C . For six z plus four | |
13:48 | . It's gonna be six . And then Z to | |
13:51 | the first power that becomes Z squared over two , | |
13:54 | four becomes foresee and then we'll add plus C . | |
13:58 | So this we could simplify it as three Z squared | |
14:03 | Plus four C Plus C . So that is the | |
14:07 | indefinite integral of 60 plus four . Try this problem | |
14:16 | . So let's say you're given the first derivative of | |
14:20 | F . And let's say it's seven . This should | |
14:26 | be the F F expert F . Prime of Y | |
14:32 | . So let's say it's seven y cube -3 Y | |
14:37 | Plus eight . And your goal is to find capital | |
14:43 | F of Y . How would you do it ? | |
14:46 | Feel free to pause the video and try it . | |
14:50 | So first let's vita mental outline of what we need | |
14:54 | to do here were given the first derivative of F | |
14:59 | . We need to find F . So F is | |
15:03 | the anti derivative of F . Prime , but we're | |
15:05 | not going to stop there . We need to find | |
15:06 | capital F . So what we need to do is | |
15:11 | we need to integrate the function two times . So | |
15:15 | we have a successive integration problem . So first let's | |
15:23 | integrate it the first time , let's find regular F | |
15:26 | . Or little F . So this is going to | |
15:29 | be the indefinite integral of F . Prime of Y | |
15:32 | . Dy . So that is the indefinite integral of | |
15:37 | seven . Y cube -3 Y Plus eight . So | |
15:46 | the anti derivative of Y to the third is going | |
15:48 | to be Y to the 4th over four . The | |
15:51 | anti derivative of why His wife squared over two . | |
15:55 | And for the constant eight , there's just gonna be | |
15:57 | eight Y based on what we have here in the | |
16:00 | UAE and then plus the constancy . So that's F | |
16:06 | . Of Y . We don't know what the value | |
16:08 | of C . Is . If we were given a | |
16:12 | point of F . F . Y , we could | |
16:15 | find see . But we'll save that for another problem | |
16:18 | . So this here is the general function of the | |
16:23 | movie . So now let's find capital F . Of | |
16:28 | Y . That's going to be the indefinite integral of | |
16:35 | F . Of Y . Dy . That is the | |
16:38 | indefinite integral of 7/4 . Why ? to the 4th | |
16:45 | -3/2 ? Y squared plus eight Y plus C . | |
16:51 | As well . And we're gonna have . Dy so | |
17:14 | the anti derivative of this , we're going to rewrite | |
17:17 | the constant And then we'll find the anti derivative of | |
17:20 | Y . to the 4th . So that's going to | |
17:22 | be why to the 5th over five . And then | |
17:26 | minus let's rewrite the constant first . So we have | |
17:30 | 3/2 . And then the anti derivative of Y squared | |
17:33 | is going to be Y to the third over three | |
17:37 | . And then it's going to be plus eight times | |
17:39 | Y squared over two . Now we have the constant | |
17:43 | of integration . See , So we're going to add | |
17:46 | a Y . To it . It's gonna be C | |
17:49 | . Times Y . And then plus a new constant | |
17:51 | which will call D . So this becomes seven over | |
18:03 | 20 . Why ? to the 5th here we can | |
18:08 | cancel the threes . So it's going to be -1 | |
18:11 | half . What's the third plus four ? Y squared | |
18:17 | plus C . Y plus T . So that is | |
18:24 | the second anti derivative of F . Prime of Y | |
18:29 | . Which is capital F . Of life by the | |
18:32 | way . For those of you who want access to | |
18:34 | the full length version of this video . Check out | |
18:37 | the links in the description section below . If you | |
18:41 | join my Youtube channel membership program , you can get | |
18:43 | access not only to the full length version of this | |
18:46 | video , but many other full length versions of other | |
18:50 | videos that I have on Youtube which you'll see over | |
18:53 | time . So feel free to take a look at | |
18:56 | that when you get a chance . Now , let's | |
18:58 | work on finding the indefinite integral of other types of | |
19:01 | functions . What is the indefinite integral of pie D | |
19:07 | theater ? Feel free to pause the video and work | |
19:15 | on that . What is the indefinite integral of E | |
19:20 | let's say E diaz . So pi is a constant | |
19:33 | . Let's compare to the indefinite integral of seven . | |
19:39 | Dy seven is a constant and we would add the | |
19:43 | variable Y to it . So this will be seven | |
19:45 | Y plus C . So pi is a constant . | |
19:48 | And here we're going to add the variable fada to | |
19:50 | it plus C . So that's the indefinite integral of | |
19:54 | pi D . Data . So remember , pi is | |
19:59 | a constant , is 3.14 with some other numbers after | |
20:03 | that . Let me find out what those other numbers | |
20:07 | are . So it's 3.14 159 2654 . With some | |
20:14 | other numbers . So whenever you see pie , it's | |
20:17 | just a constant . So treat it as if it's | |
20:21 | any of the number like seven or 8 or -4 | |
20:24 | . The same is true for E . He is | |
20:26 | not a variable , it's a constant . E . | |
20:29 | is equal to 2.7 1828 and so forth . So | |
20:39 | when looking at a problem like this is the constant | |
20:41 | , as is the variable . So this is going | |
20:44 | to be easy times , S plus C . Whenever | |
20:49 | you're finding the indefinite integral of something , you need | |
20:52 | to be able to distinguish the constant from the variable | |
20:55 | . In order to integrate it properly . Now let's | |
21:01 | focus on finding the indefinite integral of rational functions . | |
21:05 | What is the indefinite integral of one over X squared | |
21:11 | . To find this before you integrated , you need | |
21:13 | to rewrite the expression , we need to move the | |
21:16 | variable from the bottom to the top . So this | |
21:20 | is X . To the negative too . At this | |
21:24 | point we could use the power rule so we can | |
21:27 | integrate it by adding one to the exponents . So | |
21:30 | it's gonna be negative two plus one . And then | |
21:33 | divided by that result plus C . -2 Plus one | |
21:39 | . That's -1 . And after you integrate it you | |
21:44 | need to rewrite it again . So we want to | |
21:46 | get rid of this negative exploring and we can do | |
21:48 | so by moving the variable back to the bottom . | |
21:54 | So that leaves a one on top . And then | |
21:56 | we're gonna have X . To the first power on | |
21:58 | the bottom which we can just leave us X . | |
22:01 | The negative sign . I'm going to move it to | |
22:02 | the top . So the final answer is negative one | |
22:06 | over X . Plus C . Now let's try this | |
22:17 | one . What is the indefinite integral of one over | |
22:20 | X . To the fifth power dx . So feel | |
22:25 | free to pause the video and try it . So | |
22:28 | just like before let's move the variable to the top | |
22:32 | . So we have the integral of X . Race | |
22:36 | the -5 detox . And then let's add 1 to | |
22:39 | that . So negative five plus one is negative four | |
22:43 | . And then we're going to divide by that result | |
22:46 | . Next let's rewrite the expression . So we're going | |
22:49 | to move the variable back to the bottom and the | |
22:52 | negative sign . We're going to move it to the | |
22:53 | top . So we're gonna have negative one . We | |
22:58 | have a four on the bottom and X . And | |
23:01 | then this negative four becomes positive for plus C . | |
23:05 | So negative 1/4 . X . To the fourth plus | |
23:07 | C . That is the indefinite integral Of one over | |
23:12 | X to the 5th power . Try this . Finally | |
23:18 | indefinite integral of seven over X cube dx . So | |
23:27 | like before we're going to move the variable to the | |
23:29 | top . So we're going to rewrite The integral . | |
23:33 | So this is seven X . to the negative three | |
23:37 | detox . And that was integrated . So negative three | |
23:42 | plus one . That's negative two . And then we're | |
23:46 | gonna divide by negative two and then we'll have plus | |
23:48 | C . So next we're going to move the variable | |
23:52 | back to the bottom and the negative sign . I'm | |
23:54 | going to move to the top . So this becomes | |
23:57 | -7 . We have two on the bottom and we | |
24:03 | have X squared as well . So it's negative seven | |
24:07 | over two X squared plus C . So that's how | |
24:10 | you can integrate rational functions . Go ahead and try | |
24:20 | this expression Finally indefinite integral of five . Exodus seven | |
24:26 | -9 over x squared plus four x -8 dx . | |
24:36 | So this is going to be five exit eight over | |
24:40 | eight . Now for negative non X squared , we | |
24:43 | need to write that as -9 X . to the | |
24:46 | negative too . So that's gonna be negative nine X | |
24:50 | . Negative two plus one is negative one divided by | |
24:53 | negative one . And then for four X . To | |
24:55 | the first power , that will be four x squared | |
24:58 | over two and then minus attacks plus C . So | |
25:04 | we can rewrite this as 5/8 . Exit eight plus | |
25:11 | nine . The two negative signs will cancel and then | |
25:14 | we can move the X variable to the bottom . | |
25:19 | So it's plus , whoops , It's plus nine over | |
25:24 | X . And then plus two X squared -8 X | |
25:32 | . Policy . So that is the indefinite integral or | |
25:36 | the anti derivative of this expression . Now what is | |
25:46 | the anti derivative of one of her ex Zodiacs ? | |
25:51 | What do you think we need to do here ? | |
25:54 | Well , if we were to try the same approach | |
25:56 | that we've been using for rational functions , let's say | |
26:00 | if we were to rewrite the expression by moving X | |
26:03 | to the top , We would get the indefinite integral | |
26:05 | of X to the -1 . Detox . Now using | |
26:10 | the power rule , if we add 12 -1 will | |
26:13 | get excited zero . And if we were to divide | |
26:16 | by that result , we would get something that is | |
26:20 | undefined . So this technique doesn't work for one of | |
26:24 | the acts . Instead , this is an integral that | |
26:28 | you should commit to memory . The integral of one | |
26:31 | of the X . Dx is simply L . N | |
26:34 | . X . To me , I want to add | |
26:36 | that to your list of notes . And if you | |
26:41 | recall the derivative of Ellen you where you as a | |
26:49 | function of X . Is you prime over you ? | |
26:54 | So the derivative of Ln X . It's gonna be | |
26:59 | you prime . If you S X . You prime | |
27:03 | the derivative exes one . So we get one over | |
27:06 | x . So that's the anti derivative of one over | |
27:10 | X . To the first power . So if the | |
27:15 | anti derivative of one of her access L N X | |
27:18 | . What is the anti derivative of one over X | |
27:22 | plus three ? This is simply the natural log of | |
27:30 | X plus tree . So based on that , go | |
27:44 | ahead and find the anti derivative of the following expressions | |
27:49 | one over X -5 DX . Five over X plus | |
27:57 | two dx and seven over X plus four dx . | |
28:07 | So this is going to be the natural log Of | |
28:14 | X -5 Plus C . Now typically if your answer | |
28:20 | is like different than L . N . X . | |
28:22 | Normally you'll see an absolute value around X -5 . | |
28:26 | And the reason for this is that you can have | |
28:29 | a negative number inside the natural log , it's gonna | |
28:31 | be like it's going to give you an error in | |
28:34 | the calculator . So typically you'll see an absolute value | |
28:38 | symbol for expressions that can be negative For the next | |
28:44 | one . Let's move the constant to the front . | |
28:48 | So think of this as five times the integral of | |
28:53 | one over X plus two D . Ax . So | |
28:56 | this is going to be five times the natural log | |
29:00 | . And let's put our absolute value symbol . So | |
29:04 | it's five alan X plus two plus the constant of | |
29:11 | integration for the next one . Let's do the same | |
29:15 | thing . Let's move the constant to the front . | |
29:20 | So this is going to be seven natural log X | |
29:28 | plus four and then plus C . So that's how | |
29:34 | you can integrate rational functions . Where the denominator is | |
29:38 | a linear function like X plus two , x minus | |
29:40 | five and so forth . Now here's a general formula | |
29:48 | that you can use when integrating rational functions . Like | |
29:52 | one of you will use the function of X . | |
29:56 | It's gonna be one over you , prime times the | |
30:03 | natural log of you plus C . Now this works | |
30:11 | if this is a big if if you is a | |
30:14 | linear function in the form A X plus B . | |
30:18 | Now it could be zero . BkB zero , Wolf | |
30:22 | , a zero doesn't work , but BkB zero . | |
30:27 | But you have to be a linear function in that | |
30:29 | form . If there's like an X squared or an | |
30:31 | X cube , this formula is not gonna work . | |
30:34 | So let me repeat that . You have to be | |
30:36 | linear function if you have a square root of X | |
30:39 | or anything , but exit the first power . This | |
30:42 | will not work . So now let's try some harder | |
30:46 | examples Based on that . What is the indefinite integral | |
30:50 | of one Over three Acts Plus 4 ? And let's | |
30:55 | compare that to the indefinite integral of one over X | |
30:59 | plus seven . So in this case we can see | |
31:04 | that you is three x plus four the derivative of | |
31:09 | you which is you crime . The derivative of three | |
31:13 | accessory . The derivative of four is just nothing . | |
31:17 | See you prime mystery . So this becomes 1/3 . | |
31:20 | Ellen absolute value three acts plus four and then plus | |
31:33 | city . So this fraction is a result of the | |
31:39 | derivative of that expression . For the next one the | |
31:44 | derivative of X plus seven inches one . He had | |
31:47 | the derivative of three x plus four stream . So | |
31:50 | that's why you got to incorporate that . So for | |
31:53 | the next one you is going to be X plus | |
31:55 | seven and you prime . It's just going to be | |
31:58 | one . So this becomes Ellen absolute value X plus | |
32:04 | seven plus C . So no one that go ahead | |
32:14 | and try these two . Oh by the way , | |
32:19 | let's go back to what we had before . Let's | |
32:22 | prove that this is indeed the right answer . So | |
32:30 | let's find the derivative of one third times Ln three | |
32:38 | x plus four . So this is going to be | |
32:44 | won over three . And keep in mind the derivative | |
32:48 | of L N X . Or Ellen you rather is | |
32:53 | you prime over you . So the you part is | |
32:56 | what is inside of the natural log function . And | |
33:00 | so that's three X plus for you prime the derivative | |
33:04 | of three X plus four is history And the derivative | |
33:08 | of C . is zero . And so when we | |
33:12 | cancel the threes , we're going to start with our | |
33:16 | original function , which is what we have here . | |
33:21 | So that shows you that the process works . |
Summarizer
DESCRIPTION:
This calculus video tutorial provides a basic introduction into antiderivatives. It explains how to find the indefinite integral of polynomial functions as well as rational functions.
OVERVIEW:
Antiderivatives is a free educational video by The Organic Chemistry Tutor.
This page not only allows students and teachers view Antiderivatives videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.