Examples of SubSpaces and Non SubSpaces of Polynomial Space
Вставка
- Опубліковано 2 жов 2024
- Join this channel to get access to perks:
/ @drmathaholic
In this video we will see subsets of polynomial space which are subspace and which are not subspace.
Set of all polynomials whose degree is almost n ( less equal n) forms a subspace of polynomial subspace.
Set of all polynomials whose degree is = n ( equal to n) do not form a subspace of polynomial subspace.
Set of all polynomials whose degree is greater than n do not form a subspace of polynomial subspace.
Set of all polynomials such that p(0)=0 forms a subspace.
Set of all polynomials such that p(0)=1 do not form a subspace.
Sir if degree of n greater than equal 1 h to tb ye subspace hoga ya nhi... please reply
Nai Hoga..
F(X)= X AND G(X)= -X.
Both are of degree 1 but addition is not of degree greater equal 1
Okay sir
@@Shiksha291 👍
sir agr hm x ki power n positive lyn to wo W ko belong krta hy phr wo subspace ho gi
Sorry, I didn't get your question.
sir i am saying that if we let positive x power 4 instead of negitive it will become
2x power 4 and it belongs to W
@@mathematicalsociety9928 yes correct...
But then, I am giving counterexample.
So I have one specific example..
That is , addition need not always belong to W.
❤❤
Thankyou so much sir u saved me 💐💐💐💐
Welcome :)
sir can you prove a polynomial with degree >=n
please see at 6:45 . There you will see that taking x^{n=1} and - x^{n+1} +1 and adding will give a poly of degree less than n. so its not a subspace
It cleared all my doubts ✌️
Great..
Happy to hear that :)
Very interesting ❤
Clear sir 👍👍👍
Great👍😊
Let V=P2(R). Then which of the following subsets of V are subspace of V.
i. S1={p belongs to V: p'(1)=0}
ii. S2= {p belongs to V: p(-1)=1}
Sir I am confused on how to start this ques.
Have you seen 4 and 5th question in the video?
Same idea..
(i) is the subspace
(ii) is not as 0 polynomial does not satisfy the given condition..so (ii) is not a subspace..
@@DrMathaholic Yes Sir !
Is this solution correct as well:
ii.Let p1,p2 belongs to W this implies p1(-1)=p2 (-1)=1
p=alpha.p1+p2
p(-1)=alpha.p1(-1)+p2(-1)
p(-1)= alpha +1
p(-1) =1 for only alpha=0 and not for all values of alpha belongs to R.
Therefore it is not a subspace.
Is this correct as well?
@@thetechblogger5385 yes...correct
@@DrMathaholic Thank you Sir
You are helping me a lot!
@@thetechblogger5385 welcome..
Is polynomial at most degree 2 a subspace if p’(x) = x?
You mean S={ p(x) | deg p(x)
@@DrMathaholic and their addition also then gives 2x
Thanks a lot for your reply!!!
@@Learnwithme.07 yes correct..
Welcome..
How to find dimension of a subspace such that p(x)=p(2x) is satisfied
take p(x) = ax+b and use the condition, we get a=0. take p(x) = ax^2+x+c and use the given condition , we get a=0 and b=0. Similarly we always get all coefficients 0 except constant. So p(x) = c. so I think dimension is 1. Do you have the answer key?
@@DrMathaholic yes sir I got it. I do not have the answer key but your explanation is right. Dim will be 1. Thank you sir ❤️
@@ankitchowdhury8575 great..
Sir can you solve this set as a subspace of P
i.e
{p€P / degree of p=4 }
This set is not subspace can you give us example for this plz.
X^4 and -x^4+x.
Addition is not a poly of deg 4
Thankyou sir
@@ojosworld2648 welcome
Plz.give examples for these also
1.{p€P / degree of p≤3 }
Subspace ,yes
2.{p€P / degree of p≥5}
Subspace ,no
3.{p€P / degree of p≤4 and p'(0)=0}
Don't know?
4.{p€P / p(1)=0}
Subspace yes
Help me with all the questions through examples.
@@DrMathaholic ??
Sir I didn't get one question. The question is ' Let V=P2(R). Then W={a0x^2+a1x+a2 belongs to P2 : a0+a1=0} is the subspace of V or not?
It's a subspace..
Try to prove it..if you get stuck then write down that step, I will check..
@@DrMathaholic Let u,v belongs to P2 and alpha belongs to R.
u= a0x^2+a1x+a2
v= b0x^2+b1x+b2
For this to be a vector space
alpha.u +v =(alpha.a0+bo)x^2+(alpha.a1+b1)x + (alpha.a2+b2)
What to do after this?
Did I assume everything correct?
@@thetechblogger5385 a0+a1=0 and b0+b1=0 so in u+v coefficient of x^2+ coefficient of x = a0+b0+a1+b1=0 . So the condition is satisfied. So u+v is in W.
@@DrMathaholic Yes Sir u+v is in W but how to prove then scalar multiplication? i.e. alpha.u belongs to W if aplha belongs to R
@@thetechblogger5385 alpha u= alpha*a0+ alpha*a1= alpha*(a0+a1)=alpha*0=0.
So alpha*u is in w
Sir why 3 degree polynomial is not a vector space ..
If it is ..then how?
Plz help me with this doubt
Sir plz tell me
Degree = 3 can't form a subspace..
Take p(x)= x^3 and q(x)= -x^3+ x
Then p +q = x which is a polynomial of degree 1 and not of degree 3.
@@DrMathaholic sir ..we can do it same for p4 .
then why p4 is a vector space
Plz tell..
@@DrMathaholic plz reply sir
@@navjotzsingh P4 is what?
If you are taking polynomials of degree less equal 4 then yes, it's a subspace.
But if you are taking equal to 4 then it's not a subspace
Thank you sir
Welcome :)
What If U = { f € P/f has rational coefficient} is subspace or not???
No..
Take f from U and pi a real number which is not rational..
Then pi*f does not belong to U as coefficients are no more rationals...
@@DrMathaholic ok thank you so much sit it's really mean lots ❤️❤️
@@lightdevil7143 👍😊
@@DrMathaholic Is S={ (x,y,x)| |x| = |y| =|z| } space of a vector space ? this is not V.S right because When we do -a(x,y,x) is not in S . Is this right
@@lightdevil7143 not because u=(1,-1,1) and v=(1,1,-1) are in S since modulus of each element is 1 but u+v=(2,0,0) and here |2| not equal to |0|
Sir please suggest a way to prepare theorems?
Sir can you prepare a lec on Span of Subset?
Hi,
Yes, I want to make but occupied with college work..hopefully soon.
Regarding theorems, just try to understand the meaning and make sure step by step proof is clear..
Any queries then you can ask here.
@@DrMathaholic Ok Sir
Thank you so much Sir! :)
@@thetechblogger5385 welcome
Have you seen this lecture on span??
ua-cam.com/video/cui5yxBWpkQ/v-deo.html
@@DrMathaholic Sir can you please explain the proof of the theorem "If S is a non-empty subset of a vector space V, then [S] is the smallest subspace of V containing S."