Math Problem Statement

In each part, find two unit vectors in 2-space that satisfy the stated condition. (a) Parallel to the line y = 3x + 2

Solution

To find two unit vectors in 2-space that are parallel to the line y=3x+2y = 3x + 2, we first need to identify the direction of this line. The equation of the line is in the form:

y=mx+by = mx + b

where mm is the slope of the line. Here, the slope m=3m = 3, which means the line has a direction vector proportional to 1,3\langle 1, 3 \rangle, since a slope of 3 corresponds to a rise of 3 units for every run of 1 unit.

Step 1: Find the direction vector

The line's direction vector is 1,3\langle 1, 3 \rangle. To find a unit vector, we first normalize this vector.

The magnitude (length) of 1,3\langle 1, 3 \rangle is:

Magnitude=12+32=1+9=10\text{Magnitude} = \sqrt{1^2 + 3^2} = \sqrt{1 + 9} = \sqrt{10}

Step 2: Normalize the vector

To make this a unit vector, we divide each component of the vector 1,3\langle 1, 3 \rangle by its magnitude 10\sqrt{10}:

Unit vector=110,310\text{Unit vector} = \left\langle \frac{1}{\sqrt{10}}, \frac{3}{\sqrt{10}} \right\rangle

This is one unit vector in the direction of the line.

Step 3: Find the opposite unit vector

Since the line extends in both directions, there is also a unit vector in the opposite direction. This is simply the negative of the previous unit vector:

Opposite unit vector=110,310\text{Opposite unit vector} = \left\langle \frac{-1}{\sqrt{10}}, \frac{-3}{\sqrt{10}} \right\rangle

Final Answer:

The two unit vectors parallel to the line y=3x+2y = 3x + 2 are:

  1. 110,310\left\langle \frac{1}{\sqrt{10}}, \frac{3}{\sqrt{10}} \right\rangle
  2. 110,310\left\langle \frac{-1}{\sqrt{10}}, \frac{-3}{\sqrt{10}} \right\rangle

Would you like more details or have any questions?

Here are five related questions:

  1. How do you find the direction vector from any general line equation?
  2. What is the significance of unit vectors in physics and engineering?
  3. How do you find the magnitude of a vector in 3D space?
  4. What is the difference between direction vectors and unit vectors?
  5. How do you normalize a vector in higher dimensions?

Tip: Unit vectors are essential because they provide direction without changing the magnitude of vectors. They are often used to simplify vector calculations in physics and geometry.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Algebra
Vectors
Unit Vectors
Slope of a Line

Formulas

Slope of a line: y = mx + b
Magnitude of a vector: ||v|| = √(x² + y²)
Unit vector formula: u = v / ||v||

Theorems

Unit vector theorem: Any vector divided by its magnitude becomes a unit vector
Direction vector: A vector that represents the slope of a line

Suitable Grade Level

Grades 10-12