Exam Questions: www.1stclassma... In this video I explain the factor theorem and how it can be used to factorise polynomials and solve equations. This video is intended for those studying AQA's Level 2 Further Maths GCSE.
I knew because I designed the question. I am just using it to demonstrate the theorem. In the exam they will not expect you to work out the factors without giving you one first.
thank you so much for this! reviewing my pre-calc in preparation for university calculus after a five year gap and this was for some reason one of the hardest concepts for me to remember. my textbooks and other online resources just couldn't explain in a way that made sense to me. This video helped recover faith that I'll be able to do this!
When the coefficient of x in the factor is 2(or anything not 1), why do you make it equal to 0? Like when you have 2x+1 you figure out if 2x+1=0 then x=-1/2 and then you substitute the x into the equation instead of a… how does this work
If we had (2x + 1)(x + 3)(x - 2) = 0 then what we really have is just three numbers multiplied together equalling zero. If you multiply three things together and you get 0 then at least one of them must be equal to zero so either 2x + 1 = 0 or x + 3 = 0 or x - 2 = 0 We then solve each of these to find the x values that make their brackets zero and in turn the overall thing zero. The second two solve easily by taking the opposite sign but the first one requires 2 step as you describe.
He said in the video that itd take too long to go through each one, so he chose the one that he knows is a factor, and its a factor because once subbed in for x, it = 0
I knew because I designed the question. I am just using it to demonstrate the theorem. In the exam they will not expect you to work out the factors without giving you one first.
This channel is 1x10^100000 better than my actual teachers.
Write this as an ordinary number
1,00,000 million (prob)
Way more @@fundycool1089
That's not too nice. I'm sure your teachers are also trying their best.
Most underrated gcse math tutor
thank you so much for this! reviewing my pre-calc in preparation for university calculus after a five year gap and this was for some reason one of the hardest concepts for me to remember. my textbooks and other online resources just couldn't explain in a way that made sense to me. This video helped recover faith that I'll be able to do this!
Thank you for running through this - you are really clear at explaining it :)
You're very welcome!
Why is this channel underrated.
Thanks man
Dunno. 😭
Great channel.
fm gcse in an hour thank you
When the coefficient of x in the factor is 2(or anything not 1), why do you make it equal to 0? Like when you have 2x+1 you figure out if 2x+1=0 then x=-1/2 and then you substitute the x into the equation instead of a… how does this work
If we had (2x + 1)(x + 3)(x - 2) = 0 then what we really have is just three numbers multiplied together equalling zero.
If you multiply three things together and you get 0 then at least one of them must be equal to zero so either
2x + 1 = 0
or
x + 3 = 0
or
x - 2 = 0
We then solve each of these to find the x values that make their brackets zero and in turn the overall thing zero.
The second two solve easily by taking the opposite sign but the first one requires 2 step as you describe.
the video was so helpful! thank you!
You're so welcome!
imo the grid method that tlmaths taught for factorising is way easier but still great vid as always
Yes there are actually other ways that aren’t either of those as well. I use this as for me it is fastest.
@@1stClassMaths If u have no factors at all is the only method to use trial and error to find one of the factors 1st
@@rakiri209 Yes although you know the factors will be a factor of the constant term at the end. In this course though you will be given a factor.
@@1stClassMaths
Thanks
Damn considering i replied on a comment from 3 months ago you responded pretty quickly😅
TH-cam shows me all new comments so I reply in TH-cam studio rather than actually on the video. The newest ones are at the top :)
at 5:40 how do you know so surely that 3 in a factor is there a method to work it out in the exam
he may just know it from before to save time - in the exam youd have to use trial and error to find the factors
was wondering the exact same thing
He said in the video that itd take too long to go through each one, so he chose the one that he knows is a factor, and its a factor because once subbed in for x, it = 0
he said in previous comment that they will tell u a factor in the exam
😊
They give you a factor in thr exam and make you prove it’s a factor
at 6:50 you say 4x^2 - 3x^2= 7x^2... is that correct?
Hi. If you listen again I say 4x^2 - (-3x^2).
This is 7x^2 since you are subtracting a negative.
@@1stClassMaths thank you for the reply, I get it now.
legend