Chapter 5: Problem 5
Find the point on the line \(y=2 x\) that is closest to the point (5,2)
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 5: Problem 5
Find the point on the line \(y=2 x\) that is closest to the point (5,2)
All the tools & learning materials you need for study success - in one app.
Get started for free
In \(C[0,1],\) with inner product defined by \((3),\) compute (a) \(\left\langle e^{x}, e^{-x}\right\rangle\) (b) \(\langle x, \sin \pi x\rangle\) (c) \(\left\langle x^{2}, x^{3}\right\rangle\)
Let \(\mathbf{x}\) and \(\mathbf{y}\) be linearly independent vectors in \(\mathbb{R}^{n}\) and let \(S=\operatorname{Span}(\mathbf{x}, \mathbf{y}) .\) We can use \(\mathbf{x}\) and \(\mathbf{y}\) to define a matrix \(A\) by setting $$A=\mathbf{x y}^{T}+\mathbf{y} \mathbf{x}^{T}$$ (a) Show that \(A\) is symmetric. (b) Show that \(N(A)=S^{\perp}\) (c) Show that the rank of \(A\) must be 2
(a) Let \(S\) be the subspace of \(\mathbb{R}^{3}\) spanned by the vectors \(\mathbf{x}=\left(x_{1}, x_{2}, x_{3}\right)^{T}\) and \(\mathbf{y}=\) \(\left(y_{1}, y_{2}, y_{3}\right)^{T},\) Let $$A=\left[\begin{array}{lll} x_{1} & x_{2} & x_{3} \\ y_{1} & y_{2} & y_{3} \end{array}\right]$$ Show that \(S^{\perp}=N(A)\) (b) Find the orthogonal complement of the subspace of \(\mathbb{R}^{3}\) spanned by \((1,2,1)^{T}\) and \((1,-1,2)^{T}\)
How many \(n \times n\) permutation matrices are there?
The vectors $$\mathbf{x}_{1}=\frac{1}{2}(1,1,1,-1)^{T} \quad \text { and } \quad \mathbf{x}_{2}=\frac{1}{6}(1,1,3,5)^{T}$$ form an orthonormal set in \(\mathbb{R}^{4}\). Extend this set to an orthonormal basis for \(\mathbb{R}^{4}\) by finding an orthonormal basis for the null space of $$\left(\begin{array}{rrrr} 1 & 1 & 1 & -1 \\ 1 & 1 & 3 & 5 \end{array}\right)$$[Hint: First find a basis for the null space and then use the Gram-Schmidt process.]
What do you think about this solution?
We value your feedback to improve our textbook solutions.