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moe darklight
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Question from my last LA.II assignment. I have no idea what to with it. It looked simple but now I think I don't even understand the question.
Consider the Inner Product Space P2 with the evaluation inner product at points x0=-1, x1=0, and x2=2, and consider the subspace W=span(p1,p2) where p1=1+x+x2 and p2=2-3x2. Express the polynomial p=2+x+x2 in the form w=w1+w2 where w1 is an element of W and w2 is an element of W orthogonal.
Evaluation inner product points are defined such that <p,q>=p(x0)q(x0)+p(x1)q(x1)+...p(xn)q(xn)
First I have to find an orthogonal basis for W. But I can't use three basis vectors because the question demands a combination of two vectors. — I have no idea where to go. I used Gram-Smidt to come up with two orthogonal bases v1 and v2 . . . but I can't use just these two vectors to solve c1v1+c2v2=w.
And now I'm stuck. I assume evaluation inner products are used to find the solution, but seeing as we never used them in class, and all the textbook gives is their definition, I have no idea as to how they may be useful.
Homework Statement
Consider the Inner Product Space P2 with the evaluation inner product at points x0=-1, x1=0, and x2=2, and consider the subspace W=span(p1,p2) where p1=1+x+x2 and p2=2-3x2. Express the polynomial p=2+x+x2 in the form w=w1+w2 where w1 is an element of W and w2 is an element of W orthogonal.
Homework Equations
Evaluation inner product points are defined such that <p,q>=p(x0)q(x0)+p(x1)q(x1)+...p(xn)q(xn)
The Attempt at a Solution
First I have to find an orthogonal basis for W. But I can't use three basis vectors because the question demands a combination of two vectors. — I have no idea where to go. I used Gram-Smidt to come up with two orthogonal bases v1 and v2 . . . but I can't use just these two vectors to solve c1v1+c2v2=w.
And now I'm stuck. I assume evaluation inner products are used to find the solution, but seeing as we never used them in class, and all the textbook gives is their definition, I have no idea as to how they may be useful.
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