Chapter 9: Problem 13
Find the magnitude of the given vector. $$\langle 3,5,-4\rangle$$
Short Answer
Expert verified
The magnitude is \(5\sqrt{2}\).
Step by step solution
01
Understanding the Magnitude Formula
The magnitude of a vector \( \langle a, b, c \rangle \) in three-dimensional space is found using the formula: \[\sqrt{a^2 + b^2 + c^2}\]For the vector \( \langle 3, 5, -4 \rangle \), this will substitute as \( a = 3 \), \( b = 5 \), and \( c = -4 \).
02
Substitute Values into the Formula
Substitute the values of the vector components into the magnitude formula:\[\sqrt{3^2 + 5^2 + (-4)^2}\]
03
Calculate the Squares of Each Component
Calculate the square of each component:- \( 3^2 = 9 \)- \( 5^2 = 25 \)- \((-4)^2 = 16 \)The expression becomes:\[\sqrt{9 + 25 + 16}\]
04
Sum the Squares
Add the squares of the components:\( 9 + 25 + 16 = 50 \)Thus, the expression is simplified to:\[\sqrt{50}\]
05
Simplify the Square Root
The square root of \( 50 \) can be simplified as:\[\sqrt{50} = \sqrt{25 \times 2} = \sqrt{25} \times \sqrt{2} = 5\sqrt{2}\]
06
Write the Final Result
The magnitude of the vector \( \langle 3, 5, -4 \rangle \) is:\[5\sqrt{2}\]
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.
Three-Dimensional Vectors
In mathematics, a vector is a fundamental element that has both direction and magnitude. When we talk about three-dimensional vectors, we refer to vectors that exist in three-dimensional space, represented by three components. These are usually noted as \( \langle a, b, c \rangle \) where \( a \), \( b \), and \( c \) are real numbers.
The components correspond to the vector's projection along the x, y, and z axes of a coordinate system.
The components correspond to the vector's projection along the x, y, and z axes of a coordinate system.
- The first component \( a \) represents the x-axis displacement.
- The second component \( b \) is the projection on the y-axis.
- The third component \( c \) represents the displacement along the z-axis.
Pythagorean Theorem
The Pythagorean theorem forms the backbone of calculating the magnitude of a vector in Euclidean space. It's a principle that suggests the sum of the squares of the two shorter sides of a right triangle equals the square of the hypotenuse. In the context of vectors, you can extend this theorem to three dimensions.
Instead of dealing with a simple triangle with two sides, consider a vector with three perpendicular components.
Instead of dealing with a simple triangle with two sides, consider a vector with three perpendicular components.
- Each component of the vector acts like a side of a right triangle.
- These components, when squared and summed, give a form similar to the Pythagorean theorem: \( a^2 + b^2 + c^2 \).
Euclidean Space
Euclidean space is a mathematical construct that allows us to describe most three-dimensional graphics and physical scenarios. This space is named after Euclid, a Greek mathematician, who studied geometry in a flat, two-dimensional plane, but his principles extend to three dimensions.
In Euclidean space:
In Euclidean space:
- Points are defined by coordinates, such as \( (x, y, z) \), illustrating their position.
- Distances, like vector magnitudes, are measurable using geometric formulas derived from simple geometric principles like the Pythagorean theorem.
- It provides the framework to apply formulas, like the vector magnitude, to find distances and relationships between objects in three-dimensional space.
Square Root Simplification
Simplifying square roots is an important skill, especially when dealing with vector magnitudes. When you calculate a vector's magnitude, you often encounter a square root expression like \( \sqrt{50} \). This seemingly complex number can be simplified for easier interpretation.
Simplifying square roots involves breaking down the components:
Simplifying square roots involves breaking down the components:
- Identify the largest perfect square factor of the number under the square root sign.
- For example, for \( 50 \), the largest perfect square is \( 25 \), a factor of \( 50 \).
- Rewrite \( \sqrt{50} \) as \( \sqrt{25 \times 2} \), and then simplify to \( \sqrt{25} \times \sqrt{2} \).