Chapter 12: Problem 55
Explain what is wrong with the statement. The \(x y\) -plane has equation \(x y=0\)
Short Answer
Expert verified
The XY-plane should be defined by \(z=0\), not \(xy=0\); \(xy=0\) implies the x and y axes, not a plane.
Step by step solution
01
Understanding the XY-plane
The statement asks to describe the equation of the XY-plane. The XY-plane in a three-dimensional space is defined by all points where the z-coordinate is zero (i.e., \(z = 0\)). It encompasses all possible combinations of x and y coordinates.
02
Analyzing the Given Equation
The equation \(xy=0\) suggests locations where either the x-coordinate or the y-coordinate is zero. This implies two sets of linear arrays through higher-dimensional space: the x-axis (where y = 0) and the y-axis (where x = 0). These lines in isolation do not fill the entire two-dimensional XY-plane.
03
Identifying the Error
The statement mistakes the conditions for lines through the origin for a plane. The plane is defined by z = 0, not the intersections of lines described by \(xy=0\). \(xy=0\) rather describes the union of the x-axis and y-axis in the XY-plane.
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.
Coordinate Planes
Coordinate planes are fundamental components in the study of multivariable calculus. In a three-dimensional space, there are three primary coordinate planes: the XY-plane, YZ-plane, and XZ-plane. Each coordinate plane is defined by holding one of the three coordinates constant.
- XY-plane: Here, the z-coordinate is constant at zero, meaning the equation of the XY-plane is given by \( z = 0 \). This plane includes all points where any combination of the x and y coordinates are possible, effectively forming a flat surface that extends infinitely in both the x and y directions.
- YZ-plane: This plane has the x-coordinate constant at zero, described by the equation \( x = 0 \). It represents all possible combinations of y and z coordinates.
- XZ-plane: Defined by the equation \( y = 0 \), this plane fixes the y-coordinate at zero, allowing x and z coordinates to vary.
Equations of Planes
Equations of planes in three-dimensional space are key in understanding how different surfaces are represented mathematically. The general equation of a plane is given as \( ax + by + cz = d \), where \( a, b, \) and \( c \) are coefficients that determine the orientation of the plane in space.
- The normal vector: A vector perpendicular to the plane, often denoted as \( \langle a, b, c \rangle \), helps define the plane's orientation.
- Plane equation example: The equation \( z = 0 \) is a simple plane equation where only the z-component is fixed. This specific equation represents the XY-plane.
- Misinterpretation example: The equation \( xy = 0 \) incorrectly describes a plane. Instead, it defines lines where either \( x = 0 \) or \( y = 0 \), which are individual lines on the XY-plane rather than the full extent of the plane itself.
Three-Dimensional Space
Three-dimensional space is one of the most captivating areas explored in multivariable calculus. It introduces a new level of complexity, involving length, width, and height. Each point in this space can be represented by three coordinates: (x, y, z).
- Axes of reference: The x, y, and z axes intersect perpendicularly and are crucial for defining the three-dimensional Cartesian coordinate system.
- Understanding planes: A plane can be visualized as a flat surface extending infinitely in two directions within this space, crucial for segmentation and modeling of geometrical shapes.
- Intersections and objects: Intersections between planes, lines, and other objects are common tasks, requiring comprehension of spatial geometry and the role each element plays.