Partial fraction expansion 1 | Partial fraction expansion | Precalculus | Khan Academy

[@GyaretHB]

I dont know how to thank you enough. You saved my life so many times, i always get confused in class but i dont panic because i know i can just go home and watch your videos cause you explain better than any teacher i ever had. God bless you

[@Dude17684]

Im in calc bc now, and it was funny how he started to say you could use this later for integration, which is exactly why I am here

[@QualityTuTz]

hahaha same, i'm doing this for my laplace transformation topic.

[@LAA00MY]

Same here lol feels like im living the future

[@alexanderfrazier8840]

Same

[@lordsoup4287]

same

[@rabbitpiet7182]

Ditto dude17684

[@messiawsum]

Man is teaching this like we should've learned it in basic algebra in middle/highschool and I've never even heard of this until now, in MATH142, Calculus2 in college.

[@IapitusMcHeimer]

I learned more from this 1 video then I did from 2 weeks of math lessons. This man saved my life

[@Birdsting1]

I love that you explained what was actually going on when dividing the num by the dom. Thank you for not assuming we should know that like everyone else does

[@TwiliteKingdom]

THANK YOU THANK YOU THANK YOU GOD BLESS YOU THANK YOU GOD BLESS YOU MATH IS NOT MY STRONG POINT AND THIS MAKES SO MUCH SENSE THANK YOU THANK YOU PLEASE DONT STOP SHARING YOUR AMAZING KNOWLEGE THANK YOU SOOOOOOOOOOOOOO MUCH!!!!!!!!!

[@flashcat7777]

10:50 - He speaks the truth! If you're just learning this in algebra or pre-calculus, don't forget it! You will definitely see it in all its glory in calculus and differential equations classes.

[@sin7wu]

best teacher in the world.

[@WytseZ]

solving Laplace transforms and differential equations but can't do this shit 😂

[@spiritu_alley]

Wytse Zijlstrae too😂😂😂

[@albertstains8028]

XD SAME

[@companymen42]

Same. As they say, If you don’t use it ya lose it .

[@ryancurtis1881]

Bru i searched this for solving lts

[@putodango]

woah woah watch your words

[@justinpaul3458]

I am a grad student 5 years removed from my undergrad curriculum (6 years removed from my undergrad controls class and 8 years removed from my undergrad diff. eq. course) and this was a great refresher. I will need this when I take those inverse Laplace transforms. Thank you for the video.

[@821marko]

Hello Again Mr Sal, I have never done partial fractions till two days ago and I was watching some dvd's on partial fractions and the instructor was using the A B method of decomposition and the problem was similar to this one and I kept thinking couldn't you just use a matrix type of process ? sort of divide one into the other or subtract it or something ? I did several of them but obviously could not ask a question of a fairly critical step that he did and I got tired and let it go till this evening and decided to come and see Mr Sal's perspective and lo and behold he does a simple division !!!! You just simplified the whole process, the simple elementary division explanation just reduced the whole "mess" to the lowest common denominator explanation.....I could understand to a certain degree how the instructor was doing the deconstruction but rote explanation is very frustrating to me , when I was younger in math I had to be able to "see" the entire equation in my head what am I measuring...? if you tell me to measure the volume of a swimming pool ..no problem , if I am measuring trig functions I am looking right triangles and their ratios....but without some type of explanation of the purpose of dissecting a denominator it's like cutting into a lab rat in the dark , I have no idea what I am looking , I have no idea what I just sliced into....anyway you nailed it ...again thanks....

[@Symphonion]

I am in the process of watching all your videos from the very beginning (I am only watching this one because I have subscribed to your channel and it popped up on my account), and even if I understand the first topics completely I still watch the videos just because it is such an enormous pleasure to see you explain stuff :) Thank you for being the greatest teacher I have ever had, Mr. Khan!

[@jacksonmckenzie2172]

7:45 --- 7th or 8th grade... I'm in 11th grade learning this. What school did you go to?

[@nickrock999]

shit nigga im in my second year of college lol

[@harvey2695]

+Nickon Mashhood same

[@hanumanaska292]

Jackson McKenzie I'm in 6th grade!

[@jacksonmckenzie2172]

Awesome :) Keep up the ballar pace. It will definitely pay off in the future.

[@gtr0k]

yeah I'm learning this for the first time in BC calc in 11th grade

[@cindynguyen8504]

khan is such a BAMF!! I watched his videos for bio, trig and calc.... amazing how he knows every topic YET explains it great detail!! YOU ROCK KHAN :)

[@lintuxvi]

Thank you thank you thank you Sal, I've kicked and screamed my way into Differential Equations after stuttering over my math studies for the past ten years, but this video has filled enough of the gaps so I can finally do my Laplace Transforms ;D

[@ejazahmad3983]

U r saving lives

[@iamfabulous09]

I have a calculus 2 midterm tomorrow afternoon good thing I found this video. Thank you so much for taking the time and explaining this. too bad I can't pause my professor and rewind till I understand

[@virginialikesyou]

Dear Khan, I'm in Calculus II and this video saved my butt!!!! Thanks a BILLION!!!

[@noblessus]

Yes you should match the correct numerator with the correct denominator. The factor you must choose is the same factor that won't be canceled out after you multiply the numerator by the common denominator. Otherwise you wouln't get the original fraction back. I suggest you look again @ 5:38

[@Chase0809]

Wow, thank you so much! I have a calculus class at 8am, so I'm never able to fully comprehend whats going on that early. I was having trouble on my homework, but this helped a whole bunch! Thanks again! I really appreciate you posting this. :-)

[@HASMADU]

@scorpionboy3 i use the same process! its just u find what 2 numbers multiply to give -40 and also when you add those two numbers they give -3! so -8 x 5 = -40. and when u add -8 + 5 it give -3! so yea its (x -8) (x+5)

[@LTF85199]

thax Dr. khan was very helpful, i was doing inverse laplace and diffeq with this.

[@c10seth]

I'm a Mechanical Engineering major and this was a very good brush up for my control systems class

[@jameshill7413]

Had no idea that this would come back twice, first in calc and again for inverse laplace tranforms in diffeq.

[@Musketman007]

I understand how to do this easily. I just don't understand why the method works or how it was derived. I'm in calculus now and we're doing this for integration. I always like to know how things were derived and I am clueless on this one. ;(

[@H3rkules]

This was a fantastic video, Sal! Your explanation of partial fraction expansion is infinitely better than any other I found. I had spent about an hour with a convoluted explanation from a textbook, and I'm glad I've found this video since I now got it! Thanks a lot.

[@Naryo2]

i cant believe that you learnt this in the 7th or 8th grade! thanks for the enlightenment

[@johnathonhoward9348]

khan you save my life no a daily basis....you frickin rock!

[@MrAlexhusa]

Thank you very much! I could not understand either my book of my teacher but thanks to you now I do. God bless you>

[@Dafrekknpope]

Due to the commutative property, it makes no difference what order you multiply factors. A x B = B x A. 2x4=4x2 etc.The only case order matters in multiplication is with Matrices.

[@Serotonin101]

good effort... thx

[@silencedidgood]

I love the fact that you tell us Why you would do this later in Diffy Q.!

[@Frankystein9]

This guy is AWESOME!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@noblessus]

I assume that when you say "terms" you really mean "factors" right? Because we are placing factors, and not terms under A and B. Anyway, in such case, it does NOT matter under what you place them as long as you remember which one you chose to put under what numerator and dont interchange them in the middle of your calculations (since there is no algebra law that allows interchanging numerators in this way). Remember that (a+b)+c= a+(b+c), and that A and B are just placeholders. Hope this helps.

[@arrooma]

it doesn't matter what to put under A or B .. they are just a name for constants ,,,

[@MrAvancini]

My test is in two days. You saved my life! You are much better than my professor!!

[@aS0yCz8H7Fy4SAG]

turns out i need to remember this for calculus 2 thanks for posting the video

[@_wegota2319_]

When I don't go to math class, I go to KhanAcademy ahaha

[@adityaadit2004]

Wow I never taught of this before Thanks for sharing

[@abadonslipknot]

you are my salvatore!

[@jiazhongqi]

THANK YOU SO MUCH

[@officialhopsof]

brilliant! been needing a good tutorial on this one. Can't wait until you get to more advanced problems using it. Thanks!

[@WestonAAFC]

what if its like "x+whatever = A(x+2)+B(x+2)" so the two numbers int he brackets after the x's are the same?

[@LaureanoLuna]

The way of expressing the claim at 4:47 is a bit puzzling for me. I think the proper way would have beeen something like "I claim there exist numbers A and B such that...". By the way, an explanation of why such numbers do exist wouldn't be out of order.

[@naseeradel3182]

Even though my teacher is very smart, this video just increased my understanding of partial function decomposition.

[@eduardorodriguez-oj3zc]

i like this tutor, the way he breaks math down really suits my slow brain, i am a 0 in math, i guess i can say i used to be.

[@amitgupta25121993]

just the three minutes helped me

[@pradeeptailor3192]

dy/y(1-ay) = (1/y + a/1-ay)dy Please solve

[@June28July]

Lovely!

[@fixerentert]

What if ,,wen u start with x-8. Then x+5?how do u knw which one comes the denominator of A and which one is for B?

[@DesuChanXD]

THANK YOU SO MUCH!!!!!!!!!!!!!

[@omarxawneh]

best teacher thanks alot alot you really saved me thanks again

[@undeadxazn]

ironically i was just going over this a couple days ago in a math textbook lol

[@noblessus]

This is a life saver! Thanks a lot! P.S. I can't find the link to Partial Fraction Expansion 2 on your website, had to do a youtube search to find it.

[@miralabualjadail4206]

THANK YOUUU SO MUCHHH !!THESE VIDEO USUALLY NEVER HELP ME BUT URS SOMEHOW MAGICALLY WORKED THANK U THANK U THANK U :*

[@PasanJayaweeraYashoda]

proud to say when today was the day I fully understood partial fractions and I'm 21 and studying biomedical engineering in second year.!

[@brownie8293]

"this might look like some type of magic i just did" I just died

[@GzzLuiz]

This helps a lot for Laplace and inverse Laplace transformations. Thanks a lot man :)

[@PhilipHoglund]

dude, you're awesome!

[@TiranaMeKismet]

U R GOD

[@M3Burrn]

Good Explanation, thanks

[@pricesalem]

very helpful...great explanation and example, THANK YOU!!!

[@beshjm]

we're ready to commence our partial fractions decomposition,,, maaan i love you :D

[@Blueknightex]

OMG...you just showed me how to solve this really HARD partial fraction question from my 1st assignment...Aww I should've watched this video =( I definitely lost marks on that ugh >:(

[@syberslidder]

good stuff, your my hero

[@My3BEPb]

Had good grades and skipped half a year and realized that I am not as smart as I thought I was. Thanks Raptor Jesus for Khan and these videos.

[@ernestosaboia]

Thanks Khan! You are the best

[@rockYhre]

Great! Always glad to learn something new.

[@mhuntos]

How can x=-5 when in the original equation it's divided by (x-5) thus it can't be dived by 0?

[@ahaduniamin6645]

The best teacher ever!

[@GabrielSavageMusic]

Use the KA search bar.

[@JeffPB]

Yes, very important for inverse Laplace Transforms, thank you, I forgot about this

[@kspades2530]

5:02 I put A/x-8) + B/( x+5). And I got the answer flipped. I got A = 11/13 and B=2/13

[@isavenewspapers8890]

Well, yeah, that makes sense. It doesn't really matter what we name the variables; we can call them whatever we want, like P and Q, for example. It just turned out that what you called A is what Sal called B, and vice versa.

[@kspades2530]

@@isavenewspapers8890 Yh I ended up realising, thanks

[@Zerpentile93]

You are my hero :)! I am going to use this for an integral just about now.

[@Crissix100]

In 7th grade I was taught integers, and in 8th we learned how to multiply integers. I didn't learn this until calculus 1 :(

[@PancakeMan123000]

awesome video! thanks!

[@SmarthouseChannel]

Why do I feel like dropping out of college and spending time here. :D Just Awesome!

[@ruselVPK]

Thanks! That's really good thing! I understood it! However at school i was sitting like an idiot!

[@Ashfaq9519]

thanks bro ..

[@Rich-xg2cg]

THANK YOU ! 👌

[@integralboi2900]

It’s weird how Laplace transform is way easier than this basic algebra.

[@lbobo21]

yeah..got it.. ! :D thx..

[@vanepeda6147]

i never comment on videos but thanks a lot. finals are killer.

[@scorpionboy3]

What was Sal thinking when he tried to find the roots for x^2 -3x -40. Didn´t get it. What was his thought process? Looks really useful

[@rugbyf0rlife]

the funny thing is, I am in college now doing higher tier calculus and I have never come across algebraic division like in this video. when he said he did it in 7th grtade I was like WUT

[@lightmarepeno]

If you choose the x = (-5) aren't you dividing by 0

[@SUDESHKumar-yl5lu]

very helpful and all the methods are complete,easy and very understandable...Thank You Very Much Khan Academy:)

[@WILLGYS]

Yahoo!! Finally Got ti :D

[@amitgupta25121993]

its there on the website. type the partial expansion in the search box of the site - khanacademy. org

[@QAZRUS]

Great. What program do you use for this? It is paint, or some "white bord" app?

[@woodenjaw]

I am taking differential equations and I am using this to review for the class.

[@nigelstanford4]

im in calc 2 right now and I needed this video

[@ViolaceousDreams]

i love u !

[@subhikshajayasree1126]

This is very useful..Thanks😄😄

[@tonygorogo478]

Great stuff. Awesome Crystal Clear explanation from beginning to end. Thanks.

[@balkrishnathakur7801]

helpful. . stuff. at least when u wanna learn something quick.

[@MUmair19]

Amazing way of teaching :)

[@bieberismylifesaver]

I'm like in grade 9 and I already have to put up with this.

[@DepressedRockstar]

Same here!

[@MrMikees20]

Thanks a lot