Math Problem Statement

Find the magnitude and direction (in degrees) of the vector. (Assume 0° ≤ 𝜃 < 360°.) v =

2 4  , −

2 4

|v| =

Solution

Given the vector v=(24,24)\mathbf{v} = \left(-2\sqrt{4}, -2\sqrt{4}\right), let's calculate its magnitude v|\mathbf{v}| and direction θ\theta.

Step 1: Express the Vector Components

The vector components are given as: v=(2×2,2×2)=(4,4)\mathbf{v} = (-2 \times 2, -2 \times 2) = (-4, -4)

Step 2: Calculate the Magnitude

The magnitude v|\mathbf{v}| of a vector (x,y)(x, y) is given by: v=x2+y2|\mathbf{v}| = \sqrt{x^2 + y^2}

Substituting the values of xx and yy: v=(4)2+(4)2=16+16=32=425.66|\mathbf{v}| = \sqrt{(-4)^2 + (-4)^2} = \sqrt{16 + 16} = \sqrt{32} = 4\sqrt{2} \approx 5.66

Step 3: Determine the Direction (Angle)

The direction θ\theta is calculated using: θ=tan1(yx)\theta = \tan^{-1}\left(\frac{y}{x}\right)

Since both xx and yy are negative, the vector is located in the third quadrant. Therefore, the angle θ\theta should be adjusted to be in this quadrant.

θ=tan1(44)=tan1(1)=45\theta = \tan^{-1}\left(\frac{-4}{-4}\right) = \tan^{-1}(1) = 45^\circ

However, because the vector lies in the third quadrant, the direction must be: θ=180+45=225\theta = 180^\circ + 45^\circ = 225^\circ

Final Answer:

  • Magnitude v|\mathbf{v}| ≈ 5.66
  • Direction θ\theta = 225°

Would you like more details or have any questions?

Here are 5 related questions:

  1. How do you find the magnitude of a 3D vector?
  2. What happens to the direction calculation when the vector is in different quadrants?
  3. What is the relationship between the angle and the components of the vector?
  4. How would you determine the unit vector in the same direction as v\mathbf{v}?
  5. How can you find the scalar projection of one vector onto another?

Tip: Always check the quadrant of your vector when calculating the direction to ensure the angle is accurate.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Vector Calculus
Magnitude of a Vector
Direction of a Vector

Formulas

|v| = sqrt(x^2 + y^2)
θ = tan^(-1)(y / x)

Theorems

Pythagorean theorem for magnitude calculation

Suitable Grade Level

Grades 10-12