Chapter 9: Problem 36
Find the magnitude and direction of \(\overrightarrow{C D}\) for the given coordinates. \(C(-2,1), D(2,5)\)
Short Answer
Expert verified
Magnitude: \(4\sqrt{2}\); Direction: \(45^\circ\).
Step by step solution
01
Identify the Components
First, identify the horizontal and vertical components of the vector \(\overrightarrow{CD}\). The change in the \(x\)-coordinates is \(x_2 - x_1 = 2 - (-2) = 4\). The change in the \(y\)-coordinates is \(y_2 - y_1 = 5 - 1 = 4\). Thus, \(\overrightarrow{CD}\) is described by the vector \([4, 4]\).
02
Calculate the Magnitude
The magnitude of a vector \(\overrightarrow{AB}\) with components \((x, y)\) is given by \(\sqrt{x^2 + y^2}\). For \(\overrightarrow{CD} = [4, 4]\), compute \(\sqrt{4^2 + 4^2} = \sqrt{16 + 16} = \sqrt{32} = 4\sqrt{2}\). Hence, the magnitude of \(\overrightarrow{CD}\) is \(4\sqrt{2}\).
03
Find the Direction
The direction of a vector is the angle \(\theta\) it makes with the positive \(x\)-axis, given by \(\theta = \tan^{-1}\left(\frac{y}{x}\right)\). For \(\overrightarrow{CD} = [4, 4]\), calculate \(\theta = \tan^{-1}\left(\frac{4}{4}\right) = \tan^{-1}(1)\). This gives \(\theta = 45^\circ\). The direction is \(45^\circ\) from the positive \(x\)-axis.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Vector Components
Understanding vector components is crucial when dealing with vectors in coordinate geometry. A vector can be broken down into two parts: the horizontal component and the vertical component.
- The horizontal component is the change along the x-axis.
- The vertical component is the change along the y-axis.
- Horizontal component: \(x_2 - x_1 = 2 - (-2) = 4\).
- Vertical component: \(y_2 - y_1 = 5 - 1 = 4\).
Coordinate Geometry
Coordinate geometry, also known as analytic geometry, is a branch of geometry that uses the coordinate system. It combines geometry and algebra to represent and solve equations graphically.
- Points are described by coordinates, like \((x, y)\) in a 2D plane.
- Vectors, like \(\overrightarrow{CD}\), have both magnitude and direction and can be described using their components in this system.
Magnitude of a Vector
The magnitude of a vector tells us about its length or size and is a crucial aspect when working with vectors.Let's consider the vector \([4, 4]\) from our exercise. The formula to find the magnitude \(\|\overrightarrow{v}\|\) of a vector \(\overrightarrow{v} = [x, y]\) is \(\sqrt{x^2 + y^2}\). Applying this to our vector:
- Calculate each component squared: \(4^2 = 16\),
- Add them together: \(16 + 16 = 32\),
- Take the square root: \(\sqrt{32} = 4\sqrt{2}\).
Direction of a Vector
The direction of a vector is vital to understand where the vector is pointing. It's usually expressed as an angle with respect to a reference direction, typically the positive x-axis in the Cartesian coordinate system.To find the direction, use the formula \(\theta = \tan^{-1}\left(\frac{y}{x}\right)\). Here's how it works for our vector:
- Substitute the components: \(\theta = \tan^{-1}\left(\frac{4}{4}\right)\).
- This simplifies to \(\tan^{-1}(1)\), which equals 45°.