What is Subspace: Definition and 571 Discussions

In mathematics, and more specifically in linear algebra, a linear subspace, also known as a vector subspace is a vector space that is a subset of some larger vector space. A linear subspace is usually simply called a subspace when the context serves to distinguish it from other types of subspaces.

View More On Wikipedia.org
  1. S

    Proving aX is in U if X is in Rn and U is Subspace of Rn

    Let U be a subspace of Rn If aX is in U, where a is non zero number and X is in Rn, show that X is in U THis seems so obvious... but i m not sure how to show this by a proof aX is in U and aX is in Rn for sure and U is a subspace of Rn. Is it true that if U is closed under scalar...
  2. M

    Confused on why this subspace spans R^3, matrices fun

    I'm studying for my exam on monday and i saw ap roblme that says: Determine if the following is a subspace of R^3. For it to be a subspace it has to pass 1) must have the zero vector 2) closure under addition 3) closure under multiplaication here is my work...
  3. G

    Projecting vectors from R3 onto a subspace

    I want to project a vector from R3 onto a subspace. I'll let the bases for the subspace be [a,b,c]T (my T's mean transpose) --- I have the defintion for vector projection p = (<u,v>/<v,v>)*v --- I know v will be the [a,b,c]T vector but what is u? The only thing I could think of is let it...
  4. P

    Dimension of vector subspace

    The functions e^x and e^2x I have to find the dimension of the vector subspace spanned by this set. Im not sure where to start, I do know how to solve other problems asking the same question just different function. Any help would be greatly appreciated. thanks a.p
  5. P

    Finding Dimensions of Vector Subspace Spanning a Set

    The functions e^x and e^2x I have to find the dimmensions of the vector subspace spanning the set. I understand how to solve other problems like involving matrices and row reducing, but this function i don't know where to start and how to figure out the dimensions. Any help would be greatly...
  6. M

    Understanding Vector Subspaces in R^2

    I'm having a hard time understanding some things about vector subspaces. I have two problems that I am supposed to determine if the sets are subspaces of R^2. I know both sets are not subspaces but I don't really understand why or how to prove it for that matter. Can anyone shed some...
  7. S

    Proving V⊥ is a Subset of U⊥

    Suppose U, V are proper subsets of Rn and are subspaces and U is a proper subset of V. PRove that V perp is a proper subset of U perp Ok SO let U ={u1, u2, ..., un} let V = {v1,...vn} let V perp = {x1,x2,..., xn} let U perp = {w1,...wn} certainly u1 . w1 = 0 (u1 + u2 ) . (w1+w2) = 0 cu1...
  8. E

    Basis for Subspace Spanning Three Vectors

    Hi everone, quick question: if i have 3 vectors and I need to know basis of the subspace they span, so I write each vector as rows of a matrix and when I reduce it, is it the basis of rowspace or column space of matrix that is the basis of the subspace that vectors span? Thanks in advance.
  9. P

    What is the basis for the subspace W spanned by {sin^2(x), cos^2(x), cos2x}?

    I'm stumped by this problem: let W be the subspace of C[0,1] spanned by S={sin^2(x),cos^2(x),cos2x} a) explain why S is not a basis for W it's because S not linearly independent b) find a basis for W please help me with this one... TIA.
  10. D

    Nontrivial Subspace with Equal Dimensions: Linear Algebra Example

    Hi, I'm just learning for my linear algebra exam and I wonder if somebody could give me an example of a nontrivial subspace which has as many dimensions as the original space. Thanks a lot
  11. D

    Can a Nontrivial Subspace Have the Same Dimension as Its Original Space?

    Hi, I'm just learning for my linear algebra exam and I wonder if somebody could give me an example of a nontrivial subspace which has as many dimensions as the original space. Thanks a lot
  12. J

    Is Answer to Subspace Question Acceptable?

    I just wanted to know if my answer is acceptable. Q: S={(x,y,z) E \mathbb{R}^{3} l x^2 + y^2 +z ^2 =0} Is it a subspace of \mathbb{R}^{3}? My answer: It is a subspace if x=0, y =0, z= 0 Let u=(0,0,0) u2=(0,0,0) and k be a scalar u + u2 = (0,0,0) Closed under addition...
  13. M

    Exploring the Possibility of a Subspace Sphere in TNG Season 6

    TNG season 6 Relics Well I figure that they likely don't exist. But the theory that you could construct the sphere entirely around a star. Is this even plausible? Wouldn't heat and radiation eventually build up quite a bit.
  14. R

    What is Subspace? Exploring Sci-Fi Concepts

    I have heard the term 'subspace' repeated many a time in various science fiction TV shows, Star Trek and Stargate the most notable. What is this subspace they refer to, does it really exist. Thankyou.
  15. G

    What is the Basis for the Subspace V in R3 with the Equation x+2y+3z=0?

    Hi. I need to find a base for the subspace V in R3 which has the equation x+2y+3z=0 Can someone please tell my if the space I'm looking for is [1 0 0;0 2 0;0 0 3] ? If not, please explain what I'm doing wrong
  16. J

    What is the meaning of this subspace notation?

    Hi everyone, I was hoping someone could help me with something. Could someone explain to me exactly what this expression means: H = {(a+b) + (a - 2b)t + bt^2 | a E R, b E R} the purpose is to find the dimension of the given subspace, which I know how to do, I have just never seen this...
  17. J

    What Does This Subspace Expression Mean?

    Hi everyone, I was hoping someone could help me with something. Could someone explain to me exactly what this expression means: H = {(a+b) + (a - 2b)t + bt^2 | a E R, b E R} the purpose is to find the dimension of the given subspace, which I know how to do, I have just...
  18. P

    Finding a Basis for a Subspace with a Specific Condition?

    Let V be the subspace of F([0,1],R) generated by the functions f1, f2, f3 given by: f1(x)=1/(x+1) , f2 (x) = 2-x and f3(x) = x^2 for all x element of [0,1]. Find a basis of the subspace U of V that consists of all the functions g of V such that g(0) = g(1)...
  19. P

    How can I determine if a set of vectors forms a subspace?

    Hi guys. I need some help with question #5 from my assignment. If someone can just tell me how to get the question started, it would be great. Thanks :smile: http://img34.exs.cx/img34/8320/algebra1.jpg
  20. P

    Exploring Vector Subspaces in Linear Algebra

    Hi guys. I need some help with question #5 from my assignment. If someone can just tell me how to get the question started, it would be great. Thanks :smile: http://img34.exs.cx/img34/8320/algebra1.jpg
  21. G

    Help with Subspace: Find U of R^2 Closed Under Mult.

    I have been trying this problem for hours. I can't believe I can't get it. The question is "Find a subset U of R^2 such that U is closed under scalar multiplication but is not a subspace of R^2". I know that for U to be a subspace 0 must be an element of U and U has to be closed under scalar...
Back
Top