TR3.5

Solving Systems Homework

Huxley Marvit 2021-12-22 Wed 21:10

Table of Contents

#ret #hw


1 Solving Systems

Read 1.B! Have questions. Try a couple exercises. notes: KBxChapter1B

Also, keep thinking about the group work questions from today:

  • What is the relationship between cross product and the magnitude of a vector?
    • Which vector? Assuming resultant vector, \(||a||b|sin(\theta)|\) would be the magnitude
  • How does cosine relate to dot product? Can you prove it? (HINT: think about the previous problem and the Law of Cosines.)
    • \(a \cdot b = |a||b|cos(\theta)\)
    • [abcosthetaproof.pdf]
  • *Do your best to solve the following matrix equation using matrix multiplications that correspond to row operations for systems, specifically multiplying a row by a scalar, adding two rows, and swapping the order of rows. You'll have to think about how to do these things with matrices! It may help to keep in mind what a SOLVED matrix equation looks like (in particular, what does the 3x3 matrix of coefficients look like?).*

\[

\begin{bmatrix} 1 & -1 & 1 \\ 0 & 2 & 1\\ 2 & 1 & -2 \\ \end{bmatrix}

\begin{bmatrix} x \\ y \\ z \\ \end{bmatrix}

=

\begin{bmatrix} -2 \\ 3 \\ 2 \\ \end{bmatrix}

\]

%%why.pdf%%

%%Pasted image 20210904215239.png%%