Learn how to Factor and Solve Cubic Equations in Less Than One Minute using this Super Simple Trick. Step-by-Step Tutorial by PreMath.com
Пікірлер: 209
@andrii215 жыл бұрын
Thank you so much!! Cubic equations like "x^3-7x+6" is very rare. Luckily, I found it here so your video helped me a lot. Thanks again LOL!
@suvranilchoudhury64523 жыл бұрын
maybe u just didn't focus on maths properly, it isn't at all rare.
@andrii213 жыл бұрын
@@suvranilchoudhury6452 Yeah, I am refreshing my knowledge on Math on that time since I am lazy studying Maths when I was at elementary school to half of my Senior High lel.
@suvranilchoudhury64523 жыл бұрын
@@andrii21 oh that's great
@kumarvinay57243 жыл бұрын
Hi
@minamk32822 жыл бұрын
@@andrii21 yes it is super rare ive been looking for a video explaining how to do it and i only found this one
@andrewhealey76983 жыл бұрын
I hate to be the one that makes a negative comment but this method does not work. All these examples just happen to be examples where the coefficient's add up to 0 (a+b+c+d=0) so x=1 will always be a solution. this method does NOT work because you could very easily change the leading coefficient to anything other than 1 and the 3rd term ( the 'x' term) to anything other than what is given in the examples and this method will fail outright. This method may look like it "works" for very specific Cubic's but it is not a tool I would recommend learning as it will fail for almost all other Cubic's. For example, try 3x^3 + 11x^2 - 25x + 13=0 . If you follow the same rules given in this video you will get the same factors but you get completely wrong solutions!!
@AlexonHughesАй бұрын
So what method do you use to solve these type of equations ? Just asking because I want to find the universal method for solving all types of cubic equations rather than hit and trial.
@andrewhealey7698Ай бұрын
@@AlexonHughes Thanks for replying to my comment. I posted this response such a long time ago I actually forgot about this. LOL.... for me solving any random cubic equation is a pretty specific process. I would start with synthetic division to see if there happens to be an even solution to the equation. so if x=1 or x=2 etc. happens to be a solution then you can factor (x-1) or (x-2) out of the cubic equation and the remaining quadratic can be solved with the quadratic formula. If there are NO even solutions to the equation then you can use the cubic formula (math.vanderbilt.edu/schectex/courses/cubic/) to get at least one solution. But ultimately cubics that don't have at least one even solution can be very cumbersome to deal with...... I don't even want to get into quartics like x^4 powers (major headache!!) LOL
@coolkaw44976 күн бұрын
@@andrewhealey7698 Thanks for this reply. I'm currently taking Linear Algebra (and have taken calc 1, 2 already) and had no idea how to solve these sorts of cubic equations (I don't recall ever learning this in math 😭). The method in the video just so happened to work with the polynomial I had obtained from trying to calculate the eigenvalues of a 3x3 matrix. I will look into this more reliable method now for future reference!
@andrewhealey76986 күн бұрын
@@coolkaw4497 That's really cool. I graduated with my math degree back in 2007. To be honest, I was never really taught in any college class how to solve cubic equations either. I was more or less just self taught. and like said, there is really no great cookbook recipe for how to solve cubics. They are relatively straightforward if there happens to be at least 1 whole number solution (i.e x=1, x=2,x=3 etc...) Then you can factor that solution out and you are left with an easy quadratic to solve. Without at least one whole number solution they can be a bit of a headache. But I know one thing the method taught in this youtube video is complete non-sense and will only work for very VERY specific cubics and the creator of this video really does a disservice to anyone trying to learn how to properly solve a cubic equation.
@sakthishridevis9983 жыл бұрын
I watched around six videos today on solving cubic equations, best one so far. thanks a million!
@PreMath3 жыл бұрын
Glad to hear that Sakthi! I'm sure you are an awesome student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃 Keep smiling😊
@yuvamaths2 жыл бұрын
Really fantastic method of solving cubic polynomials. Very easy and time saving method too. Thanks a lot for sharing this type of shortcut methods sir.
@janjanboquia673810 ай бұрын
does this also apply to cubic polynmials that has leading coefficients greater than one (ax3+bx2.... wer a>1
@Jonathan-vx7xi3 жыл бұрын
simple, elegant...why isn't this being taught as the norm?? thank you
@PreMath3 жыл бұрын
You are very welcome Jonathan! Thank you so much for taking the time to leave this comment. I'm glad you liked it! Your feedback is always appreciated. Please keep sharing my channel with your family and friends. Take care dear and all the best 😃
@pranavnarware63662 жыл бұрын
before seeing this video , i was also thinking about the relation between constant and any other number , but i also couldn't find the relation. Finally i see your video and understand much better
@sleepeasyguitar95055 ай бұрын
This is one of the most helpful methods I've ever learnt. Thank you!
@anuradha9283 Жыл бұрын
What a beauty man i love this method! Waiting to show off to my friends!
@user-fy2ud4fq4g2 ай бұрын
will this work for all degree 3 polynomials? what about x^3-2x^2-x+2=0
@sasmit56173 жыл бұрын
It's like now every expert mathematics teacher is Indian🥰🥰🥰🥰
@PreMath3 жыл бұрын
You are awesome my friend! Please keep sharing premath channel with your family and friends. Take care dear and stay blessed😃 Have a very happy and blessed New Year!
@ranamoh70313 жыл бұрын
but sir, when picking the three numbers I can choose different signs and get the same answer but the sign will be different so how can I choose the correct sign
@Amansingh_143 жыл бұрын
Thank you sir Your video is very helpful for me in solving cubic equations
@ayushpratapsingh25403 жыл бұрын
This is the best method of solving cubic equation i found on youtube. Thanks!
@PreMath3 жыл бұрын
You are very welcome Ayush! I'm sure you are an awesome student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@xavier60623 жыл бұрын
Sir pls tell in comment section that how to factorize this one through this method Question) x³+3x²+3x-7 Pls tell
@kfjfkeofitorhf9520 Жыл бұрын
X=1 1+3+3-7=0
@AkashSharma-fx8cq3 жыл бұрын
This is really best method to quickly and easily solve cubic equations .. thanq vry much sir ❤️
@timeonly1401 Жыл бұрын
These cubics all have 1 has a root (since sum of all coefficients = 0). Thx to your channel, a couple others, I always check +/-1 (if sum[coeffs of odd-power terms] = sum[coeffs of even-power terms, then -1 is a root). Using synthetic div to get the quotient quadratic... which can be factored using inspection, grouping, or quadratic formula to get remaining roots.
@waaahhhvishhh9408 Жыл бұрын
Amazing thanks
@SamuelLartha-rb1ni Жыл бұрын
Your the king of math thanks very much i really appreciate cause now i can work polynomials by ma self please continue with the good work
@doctorjacksonville70922 жыл бұрын
Only works if the product of the two constant in two binomial roots + the sum of the two constant in two binomial roots multiplied to the constant of the third binomial root is equal to the coefficient with the linear variable x. (x + a) (x + b) (x + c) = [a + b] [c] + [a x b] Otherwise, a different answer would pop out, which is most probably irrational or imaginary.
@kailashpandit1332 жыл бұрын
Right
@SolveMathswithEase2 жыл бұрын
Try solving this one: kzbin.info/www/bejne/m3echWaZhrd4htk
@ntandoyenkosimkhize1818 Жыл бұрын
Thank you, finally I got it.
@11alaxmitiwari483 жыл бұрын
Thanks alot sir.. sir plz clear my doubt that when there would be a no multiplied with x^3 then what changes do we need to make.
@mewingcy Жыл бұрын
Thank you so much, sir!!
@michelle-cv5tg11 ай бұрын
the best math yt channel!!!
@isaaccoleman29603 жыл бұрын
YAAAAAS!!!! thankyou so much this an immense help with exams around the corner especilly
@PreMath3 жыл бұрын
You are very welcome Isaac! I'm sure you are a brilliant and bright student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@JulesMoyaert_photo7 ай бұрын
I wish I had been taught this method in college!!! SUBSCRIBED!
@ChaniSalvi6 ай бұрын
I was looking for the Equation 1 kind of questions like how to solve them and yours video helped me..... thanks alot😊😊
@bryanjohnson2016 жыл бұрын
What about when the coefficient for the cubic expression is something other than +1?
@PreMath6 жыл бұрын
Thank you bryan johnson for this crucial point. I'm in a processing of uploading more vid tutorials that would answer your questions. Please stay tuned. Kind regards
@KaylaMarie_2 жыл бұрын
ive been looking for this as well. cant find that example anywhere
@thieskersten90842 жыл бұрын
It's equal to 0, you can divide everything by the first coefficient. 3x³+9x²+12x-15=0x³+3x³+4x-5=0 Then use the "rational root theorem"
@mjoycepalma93334 ай бұрын
Thank You :)
@simple_idiot2 жыл бұрын
Thank you🌹
@khanabdul819 Жыл бұрын
Very good explanation. Bravo.
@ecetech-lecture96362 жыл бұрын
Simply superb,
@dannykasangili31418 ай бұрын
Thank you very much you 've helped me.i didn't know that cubic function is this simple
@moth362 жыл бұрын
Thank you very much for this helpful video
@ritikarishi29033 жыл бұрын
Thanku sir ji
@GulshanKumar-zl1ip3 жыл бұрын
What we will do for high no.like 250 or 70..
@jim2376 Жыл бұрын
Very helpful. Well explained.
@HTMreal Жыл бұрын
sir what shall we do if there is a coefficient with X^3 also is it also workable if X is a fraction: the first equation
@waaahhhvishhh9408 Жыл бұрын
Just remove the fraction but multiplying all the terms in the equation by the denominator of the fraction 😁
@bolimbs Жыл бұрын
Thank you for this Sir, big help. I'm now able to give my son a clear explanation. 👍🙏👍
@krishansaini7662 жыл бұрын
Really help full video
@justaracoonchillinginatoilet693 жыл бұрын
but what if they dont multiply to make the number at the end of the equation and dont add to make the coefficient of x? im not sure how to solve x^3+x^2+2x-3, please help :(
@tokyo222dp42 жыл бұрын
Yes am like you hhhh x^3-6x+7
@vanshikarajpal14353 жыл бұрын
Finally i understood it!!
@jayaram94682 жыл бұрын
Thank you
@Saffron_Krishna3 жыл бұрын
Really nice
@wandersgirl1322 жыл бұрын
Thankyou soo much ❣️
@tibofordeyn15292 жыл бұрын
great method!
@vishnupatel63582 жыл бұрын
Thanks you sir
@archanabparchanabp12852 жыл бұрын
Thankyou sir
@chinmoydeka2841 Жыл бұрын
Omg sir u r a life saviour 😍🥰.
@vivificateurveridique142011 ай бұрын
What if we have a number before X cubic?
@optimisticgirl3332 жыл бұрын
Tq sir
@shabnamjaha19905 жыл бұрын
Thanks sir
@ritubes89423 жыл бұрын
O God unbelievable thanks a lotttttt Finally found exactly relatable vedio♥️♥️🙏🙏💐💐
@PreMath3 жыл бұрын
Excellent dear Ritu. You are awesome 👍 Take care dear and stay blessed😃 Love and prayers from the USA!
@ritubes89423 жыл бұрын
@@PreMath thank you Sir💐
@rlssrlss71583 жыл бұрын
Sir, could you please solve this equation x^3-3x^2-4x-2=0
@nishikaperera29883 жыл бұрын
Very helpful
@dreamyeyes52293 жыл бұрын
Just wowwww😃
@AZNBOOM8084 жыл бұрын
How do you use this method if you're roots are non integers?
@Exonorm273 жыл бұрын
It’s actually simple. Generally, you find all the factors of “D” term, then plug those factors into the cubic. If one of those factors let’s the equation to =0, then you have already found a solution. If that doesn’t work, then take all the “D” factors and divide them by the “A” coefficient. Plug those “(Factor-ofD) / A” into the cubic and if any of those let the cubic equation =0, then you have found one of the solutions. From there, you need to convert it from a “x=_____” into “x-_____=0”. Then use polynomial long division or synthetic division to pull out a quadratic. Factor the quadratic if possible. The other method is to just graph the cubic and use graphing technology to solve it lmao.
@joeynatividad33853 жыл бұрын
OMG TYSM NOW IT'S A LOT EASIER FOR ME TO ANSWER NOW
@PreMath3 жыл бұрын
Glad to hear that JoeyLou! I'm sure you are a brilliant and bright student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@wisemath10843 жыл бұрын
Thank you again for your amazing videos!
@SolveMathswithEase2 жыл бұрын
Try solving this one: kzbin.info/www/bejne/m3echWaZhrd4htk
@purohitabhilash30703 жыл бұрын
How to solve if A is not 1 in Ax^3
@user-sl3eo3xn1p3 жыл бұрын
can you write the final factor in binomial form for the first question? thx
@PreMath3 жыл бұрын
Yes, since the binomial form has two terms. Thanks for asking😀 Take care dear and all the best😃 Have a very happy and blessed New Year!
@harikasomisetti2561 Жыл бұрын
Greetings, In this video you are solving all cubic equations having coefficient of x^3 is 1 i.e., a=1. Can you please explain how to solve if a is not equal to 1 also. Thank you.
@armstrongmwaulusi8473 Жыл бұрын
My question too
@tangikinatua98583 жыл бұрын
Thank you so much❤. This video helps me a lot.....
@PreMath3 жыл бұрын
You are very welcome Tangikina! I'm sure you are a brilliant and bright student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@a20rahuljawale682 жыл бұрын
What if the constant is 0
@rajeshnandi44174 ай бұрын
Can we use this method in board exam sir
@Pratyai-l9z2 жыл бұрын
This trick works only in particular questions not in every question.
@hahaha-kc4zz10 ай бұрын
Little confused on the first example, my question is x^3-x-6 and it doesn’t split cleanly
@manitrathi55326 ай бұрын
X^3-7x+6 is very I found everywhere but I can not found this help me a lot
@jaideepsingh79553 жыл бұрын
Very nice sir. Sir what if the x^3 term has a coefficient ??
@brawlstars-xh7xf6 ай бұрын
Did you find your answer? because i have that question too
@mahantyruteekraj51323 жыл бұрын
Thanks sir i find this formula very much helpful
@PreMath3 жыл бұрын
You are very welcome Raj! Thank you so much for taking the time to leave this comment. I'm glad you liked it! Your feedback is always appreciated. Please keep sharing my channel with your family and friends. Take care dear and all the best 😃
@edwardwang7929 Жыл бұрын
if the sum of coefficients of all terms of a polynomial is zero, then x-1 is a factor of this polynomial.
@augustadaly6915 Жыл бұрын
An awesome simple method to factor cubic equations❤
@goldfing5898 Жыл бұрын
This to be taken with a grain of salt, since it works only in the rare case that the solutions, or at least one solution, is an integer number. It does no help for the general cubic, although such videos do always suggest...
@sanskriti99722 жыл бұрын
I need answer for this equation: y^3+3root3y^2-3y-root3
@atulsinghal42563 жыл бұрын
Thank u thank u thank million thanks to you sir💚🧡💜❤️💚
@PreMath3 жыл бұрын
You are very welcome Atul! I'm sure you are an awesome student 👍 I'm glad you liked it! Please keep sharing premath channel with your family and friends. Take care dear and all the best😃
@shivanikumhal7913 жыл бұрын
But is the name of that rule or trick
@nikhilwaghmode81172 жыл бұрын
you king
@bijoysharma11433 жыл бұрын
Thank u given nice trick..
@PreMath3 жыл бұрын
You are very welcome Bijoy Sharma! I'm sure you are a brilliant and bright student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@sudhanshubaranwal33143 жыл бұрын
How to solve x³-2x²+2x+1=0 by this method??
@jyotiprasadpegu-xd7ul11 ай бұрын
Easiest way to have factor
@darkomarkovic33732 жыл бұрын
x^3-4x^2+4x+x-2=9 So, we get after transformation, equal solution!
@jastaj..96343 жыл бұрын
Best one i saw on youtube thank u sir❣️
@W81Researcher3 жыл бұрын
What b - 3ac > 0
@waaahhhvishhh9408 Жыл бұрын
@@W81Researcher nob
@user-hk6xv8hs3r Жыл бұрын
befectoooo);
@umarmohd64182 жыл бұрын
sir in 1st positive 1 i also facotr
@pranavnarware63662 жыл бұрын
@PreMath how do we factorise 2y3 + y2 - 2y -1
@armstrongmwaulusi8473 Жыл бұрын
I tried this,,,,it was hard for me to find factors
@armstrongmwaulusi8473 Жыл бұрын
Any idea on this one
@errorsmasher4653 жыл бұрын
Thank u sir...
@PreMath3 жыл бұрын
You are very welcome Rohan! I'm sure you are a brilliant and bright student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@RajeshKumar-rf3et3 жыл бұрын
Thankuu so much sir
@PreMath3 жыл бұрын
You are very welcome Rajesh! I'm sure you are an awesome student 👍 I'm glad you liked it! Please keep sharing premath channel with your family and friends. Take care dear and all the best😃 Have a very happy and blessed New Year!
@dhanvanthsri4843 жыл бұрын
Super helped me tnks
@PreMath3 жыл бұрын
You are very welcome Dhanvanth! I'm sure you are a brilliant and bright student 👍 I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@richaparekh44463 жыл бұрын
Thanku soo much Sir!
@PreMath3 жыл бұрын
You are very welcome Richa Parekh! Thank you so much for taking the time to leave this comment. I'm glad you liked it! Your feedback is always appreciated. Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@richaparekh44463 жыл бұрын
@@PreMath Sure sir, i will😃
@vipinsawaria3 жыл бұрын
2x³+x²-5x+2=0.. can this equation solve by this method.
@kfjfkeofitorhf9520 Жыл бұрын
X=1 2+1-5+2= 3-5+2= -2+2=0
@scmtuk3662Ай бұрын
This doesn't always work though. It works with x^3 + 11x^2 - 25x + 13 But what happens if you change the co-efficient of x? This doesn't work with x^3 + 11x^2 - 24x + 13. Expanding the expression (x+a)(x+b)(x+c) gives us x^3 + (x^2)c + (x^2)b + bcx + a(x^2) + acx + abx + abc Factoring this gives us: x^3 + (a+b+c)x^2 + (ab+ac+bc)x + abc So, what we _really_ need, is three numbers that satisfy three conditions. The sum of the three numbers must be the co-efficient of x^2 The product of the three numbers must be the constant. And the sum of all possible product pairs must be the co-efficient of x. Also, unrelated to the above, but: Sometimes, however, you may end up having a situation where the numbers that multiply to give you the constant may involve fractions. For example, 13 can be made from -1, -26 and 1/2 If we take -1, -26 and 1/2 and add these together, we get -53/2 If we then take product pairs, 26, -1/2 and -26/2 then add these together, we get 25/2. Therefore, (x-1)(x-26)(x+(1/2)) would be the solutions to the equation x^3 - (53/2)x^2 + (25/2)x + 13 = 0 To remove those fractions, we could then double this, to get 2x^3 - 53x^2 + 25x + 26 = 0
@RajeshKumar-rf3et3 жыл бұрын
Best trick sir
@PreMath3 жыл бұрын
Thanks dear😀
@arsyanazhima45132 жыл бұрын
I've tried this method on different cubic equation and re-multiply them to check whether it's right or wrong and it's not always right. This solving method is too dangerous to be used, it might solve some equation of the cubic factorisation but not all of them. I do not recommend this method. but this is just my opinion on solving cautiously, if you're reckless and a simple person i don't mind. Honestly no offense, rather i respect you "PreMath" for creating such a shortcut, i couldn't done such things.
@prajwolbhatta49113 жыл бұрын
How to do x∆3-3x-2=0
@lovemirlicardo56163 жыл бұрын
Shocks, thank you so much❤️
@PreMath3 жыл бұрын
You are very welcome! I'm glad you liked it! Please keep sharing my channel with your family and friends. Take care dear and all the best😃
@subhamkumar18043 жыл бұрын
What if d is 1
@justinmudimbu21073 жыл бұрын
What about expressions like 6X^3+11X^2-4X-4😭
@PreMath3 жыл бұрын
Thanks dear for the visit! You are awesome 👍 Take care dear and stay blessed😃 Kind regard
@RipunjayDeka2 жыл бұрын
Thank you very much Sir And please help me to solve it x^3-7x^2+36
@RipunjayDeka2 жыл бұрын
That means in this format ax^3+bx^2+c=0
@kfjfkeofitorhf9520 Жыл бұрын
X=3 27-63+36= -36+36=9
@shridz_ Жыл бұрын
Doesn't work for 4x³-6x²+1=0
@e-learningwithsomendrasing25653 жыл бұрын
Thanku sir
@PreMath3 жыл бұрын
You are very welcome dear. Take care dear and stay blessed😃
@celinerajaram93273 жыл бұрын
what do i do if the last number is a fraction?
@PreMath3 жыл бұрын
Dear Celine, in that case, you won't be able to solve it that quick as the problem is going to get complicated. We may have to take different route to solve for that case. Hope I answered your question. Take care dear and all the best😃 Have a very happy and blessed New Year!
@celinerajaram93273 жыл бұрын
thank you, i figured it out it wasn’t easy. but this video was very helpful!
@NamanPaliwal195 жыл бұрын
What will happen if equation is x³-x-6=0
@abdeslamelhaddouchi98575 жыл бұрын
The solution of thé équation is : (x-2)(x^2+2x+3) = 0 s={2 ; -1+2√2 ; -1-2√2 }
@KeithInModesto4 жыл бұрын
@@abdeslamelhaddouchi9857 I think you may have mistyped this. It should be: s = {2, -1+i√2, -1-i√2} Whereas if you plug in say (-1+2√2) into f(x) = x³-x-6, you get f(-1+2√2) = -30 + 20√2 [or f(-1+2√2) = 10(-3 + 2√2)]
@RubaschMath3 жыл бұрын
Naman - you can try my method here: kzbin.info/www/bejne/fmbcaqGHZcaVe9E