Blessing in disguise you make the Integrals look easy and very understandable. I am longing for a lecture video like this and I'm glad I found you. I appreciate your effort.
When you use integration by parts in the last question of the video, you get another integration by parts: xsin(xPower2)- what is the integral of sin (xpower2)?
Just take u = x^2 then du = 2x dx we see there is x on top so we multiply by two on top and take out 1/2 of the integral to make it equal. Then the integral becomes 1/2 sinu du which is -cosu/2 subsitute back for u and you will have your answer.
i know it's a very late reply, but in case someone sees it- To keep it simpler and less confusing, integrate by keeping it in the substituted form only ie. _usinu du_ , while integrating by parts Then put _u = x^2_ in the final answer
Best explanations clear cut and simple to understand. I wish I had access to this tutorial when I was doing grade nine. Was looking for this all these years.
15:30 This problem can be solved a bit more easily, by keeping the expression in _usinu_ du form while integrating it by parts Then only putting u = x^2 in the end
Hi, What is the integral of ; If f( x,y ) = k power - ( x+iy) , k > 0 is a Real constant number ? A) relative to x B) relative to y C) relative to x , y Thanks,
The ending quiz doesn't make sense to me. Along the way you get -Integral (-(cosx^2 / 2) * 2x) dx. This seems like another product. Wouldn't this kind of integration by parts continue ad infinitum? The 2x there also looks like it vanishes from thin air. There must be something I am misunderstanding here.
Finally got there. ∫ [- (cos^2)/2] 2x dx The 2s cancel out, leaving ∫ - (cos x ^2) x dx pull - through, - ∫ (cos x ^2) x dx use substitution, u = x^2 therefore du/dx = 2x. Move dx to the other side. du = 2x dx. Divide by 2 to get x dx on its own, to match what's left in the original expression after substitution du/2 = x dx -∫ cos u * (du/2), break du/2 into du * 1/2 -∫ cos u * du * 1/2, pull 1/2 through - 1/2 ∫ cos u du, ∫ cos u du is a standard trig integration, ∫ cos u du => sin u -1/2 * sin u. Combine terms -(sin u /2) replace u with substitute term. - (sin x^2)/2
@@ProfessorDaveExplains you deserve it. you already probably know, but highlighting what is being talked about in red is what separates you from other youtubers. the viewer never gets lost! it's great!
Superb explanations. Thanks a lot for sharing. By the way, I didn't get a point here, why can't we evaluate ∫cos√x.dx to -sin√x+c? that looks pretty straight forward, right? And also, I found sometimes the constant hasn't been added after evaluating the indefinite integrations. How does it actually work?
I’m not sure what your thinking is but the integral of cos(sqrtx) is not that. try taking the derivative of -sin(sqrtx) you will get something different. So no it’s not that straight forward.
we can't because √x is considered a function itself so, cos√x is cos of a function of x let's say x is an angle, so cos(x) is valid but √x is not an angle, it's a function of the angle x
Hello professor dave, I hope you would notice me, this u-subtitution method.. I used this on my test. All my answers were marked wrong, I follow exactly how would you manipulate the problem so it will look alike as the basic formula for integration. However he invalidate my reasons that I learned it on RUclips, I had lots of references. Your Videos, The Organic Chemistry Tutor, and more youtubers and registered Mechanical engineers. What he said was it was too complicated for him to look our papers. Idk what to say to him, he's a registered and topnotcher on board exam, way back 90s. He just invalidate our reasons. We are not taught in school these calculus things, we are just given the coverage and after a few weeks he gives the test. No teaching, we are purely self-paced learning. Please help me, how would I let him know that this kind of method / technique exists. We showed him the demo of how it is solve he just keep invalidating our reasons.
When I get graduated from my career I will give you 500 bucks, thank u for all the support and highquality videos.
When I become a millionaire il give half of it (if I pass maths of course)
yo did you do it?
up
Did you give him now?
@@ARN48411 he ded
You make it look so easy.
Robert Zanatta
That's one flaw of teacher
They may fill you with illusion of knowledge
@@gretawilliams8799 well said
@@gretawilliams8799 like do you wanna understand the concepts or not?? lmao how is it illusion if you are actually learning.
I wish I took my early Trigonometric and Calculus classes seriously.
Where has my failure brought me; back to you!
facts especially trig
11:43 one of the most helpful statements i've heard on the topic
Blessing in disguise you make the Integrals look easy and very understandable. I am longing for a lecture video like this and I'm glad I found you. I appreciate your effort.
I love your intros
He knows a lot about the kinds of stuff, professor dave explains.........OOMMMMMM
dammm. I'm just wonder the lyrics for this and immediately see this comment!!
the way i felt when i solved the check comprehension on my own and got it right was absolutely blissful
Thank you very much sir! You are a big help through my education, I check your all kinds of videos.
Thank you prof your vids really helped me get out of fear of integral calculus ❤️
When you use integration by parts in the last question of the video, you get another integration by parts: xsin(xPower2)- what is the integral of sin (xpower2)?
i also dont understand how he got that integrand. i`m getting a different answer. 2sinx^2 is =-cosx^2/2....but we have xsinx^2
Just take u = x^2 then du = 2x dx we see there is x on top so we multiply by two on top and take out 1/2 of the integral to make it equal. Then the integral becomes 1/2 sinu du which is -cosu/2 subsitute back for u and you will have your answer.
i know it's a very late reply, but in case someone sees it-
To keep it simpler and less confusing, integrate by keeping it in the substituted form only ie. _usinu du_ , while integrating by parts
Then put _u = x^2_ in the final answer
Best explanations clear cut and simple to understand. I wish I had access to this tutorial when I was doing grade nine. Was looking for this all these years.
I like your philosophical, strategical approach
Thank you. Your maths videos are very helpful. Way better than the ones at my uni.
The voices in my head have resumed screaming.
I can see the degree of your study about integration. Great.
Omg, i have no words for you, just just really big appreciate for you dear🙏🏼
15:30 This problem can be solved a bit more easily, by keeping the expression in _usinu_ du form while integrating it by parts
Then only putting u = x^2 in the end
cannot thank you enough!! this is super helpful!!! :)
4:13 - No need - (sqrt(u))'=1/(2sqrt(u)) ;F(1/(2sqrt(u))=sqrt(u). No need do more that need
This is the only man I'll watch the entire ad for
Hi,
What is the integral of ;
If f( x,y ) = k power - ( x+iy) , k > 0 is a Real constant number ?
A) relative to x
B) relative to y
C) relative to x , y
Thanks,
I tought I'm the only one confused at 6:53, until I saw it was most replayed, hahahah.
If you want him to earn money but can't afford patreon, just watch the whole of the skippable ad
I don’t think that will help. Ad sense is given only for the unskippable version of a skippable ad.
@@Fumbiver
Wait, really? Are you sure?
The ending quiz doesn't make sense to me. Along the way you get -Integral (-(cosx^2 / 2) * 2x) dx. This seems like another product. Wouldn't this kind of integration by parts continue ad infinitum? The 2x there also looks like it vanishes from thin air. There must be something I am misunderstanding here.
Thanx Prof Dave!
I watched this before my exam took notes and think I might have passed my exam. Thank you!
Well explained
Hi, would you be able to make a video on partial fraction decomposition method for integration?
Are you an A level student? I study those too! This dude is a wonderful teacher.
Amazing video professor.. keep it up..
I solved em all!!
The next video is not coming !! Btw u r just awesome !!
Wow u made all these master pieces within 1 day ? I just noticed what you wear.
Great Job!
Please do a video about matrices
linear algebra is coming soon!
there is an erro in 2:30 which the anti-derivative of tanx is wrong
no these are all correct
@@ProfessorDaveExplains I'm really sorry, I made a silly mistake
Nice presentation 💖
1:53 i can spot a mistake there in your chart..
Integral of a^x is equal to a^ x times lna) ie
¶a^x = a^x.lna + c
Isn't that the rule for exponential derivative
thats the derivative :\
Love from INDIA❤️❤️❤️❤️❤️
Thanks
super helpful prof ❤
I don't understand how the 2x on the right hand side of the second to last line of the comprehension disappears.
Finally got there.
∫ [- (cos^2)/2] 2x dx
The 2s cancel out, leaving ∫ - (cos x ^2) x dx
pull - through, - ∫ (cos x ^2) x dx
use substitution, u = x^2
therefore du/dx = 2x. Move dx to the other side.
du = 2x dx. Divide by 2 to get x dx on its own, to match what's left in the original expression after substitution
du/2 = x dx
-∫ cos u * (du/2), break du/2 into du * 1/2
-∫ cos u * du * 1/2, pull 1/2 through
- 1/2 ∫ cos u du, ∫ cos u du is a standard trig integration, ∫ cos u du => sin u
-1/2 * sin u. Combine terms
-(sin u /2) replace u with substitute term.
- (sin x^2)/2
How do you prove that it's literally impossible to integrate certain expressions?
Wow!
Didnt know integrals were so awesome!
I thick end of this year or next year you will have 1 million subscribers.
I'm gonna get there in about four weeks.
@@ProfessorDaveExplains you deserve it. you already probably know, but highlighting what is being talked about in red is what separates you from other youtubers. the viewer never gets lost! it's great!
Superb explanations. Thanks a lot for sharing.
By the way, I didn't get a point here, why can't we evaluate ∫cos√x.dx to -sin√x+c? that looks pretty straight forward, right?
And also, I found sometimes the constant hasn't been added after evaluating the indefinite integrations. How does it actually work?
I’m not sure what your thinking is but the integral of cos(sqrtx) is not that. try taking the derivative of -sin(sqrtx) you will get something different. So no it’s not that straight forward.
we can't because √x is considered a function itself
so, cos√x is cos of a function of x
let's say x is an angle, so cos(x) is valid but √x is not an angle, it's a function of the angle x
excellent
The GOAT
this is hard fr
That’s me in 9:52
Hello professor dave, I hope you would notice me, this u-subtitution method.. I used this on my test. All my answers were marked wrong, I follow exactly how would you manipulate the problem so it will look alike as the basic formula for integration. However he invalidate my reasons that I learned it on RUclips, I had lots of references. Your Videos, The Organic Chemistry Tutor, and more youtubers and registered Mechanical engineers. What he said was it was too complicated for him to look our papers. Idk what to say to him, he's a registered and topnotcher on board exam, way back 90s. He just invalidate our reasons. We are not taught in school these calculus things, we are just given the coverage and after a few weeks he gives the test. No teaching, we are purely self-paced learning. Please help me, how would I let him know that this kind of method / technique exists. We showed him the demo of how it is solve he just keep invalidating our reasons.
Man u da best
You are right, just like chess, it's an art.
Dis trippy bruh
WOW
The you is dizzy.
Ur methodology quite differs from others
Can u solve one proplem for me?
haha hard to tell if you are talking to me or refering to the substitution "u", pretty funny if you think about it
AOW
I don"t think this can be called advanced
man wtf
I put a dislike cause I didn't understand this video.
Integration is not like a sport...math is nothing like a sport. Math is just frustrating.
Just need to practice
Being good at it will make frustration go away.
Try something , if it doesn't work
try something else
- Prof. Daves
12:26