Should I use 2D or 3D graphs for Implicit Functions?

In summary, the speaker is learning about implicit functions and is having trouble graphing them using MathGV. They are unsure whether to choose 2D or 3D graphs and are struggling with solving for x or y. They ask for clarification on whether a 3D graph truly represents a 3D function. The responder explains that functions are not classified as 2D or 3D, and that implicit functions are technically relations. They suggest trying 2D graphs with polar coordinates instead of cartesian coordinates.
  • #1
DrummingAtom
659
2
I've began learning some Implicit Functions but graphing them seems to be a problem. I'm using MathGV for graphing. Should I choose 2D or 3D graphs? It's not graphing with 2D, and solving for x or y would be an even bigger problem.

For instance, 3(x^2+y^2)^2 = 100xy will graph in 3D but is this really a 3D function?

Thanks.
 
Physics news on Phys.org
  • #2
DrummingAtom said:
For instance, 3(x^2+y^2)^2 = 100xy will graph in 3D but is this really a 3D function?

There is no such thing as a "3D function" or a "2D function". Functions are functions. They are maps. They take input values and produce output values. Sometimes those input and output values are real numbers. Sometimes they are points in space. But we don't call them 3D or 2D functions.

Implicit functions aren't really functions. They are bastardizations. More technically, they would be called relations. You can think of it as a statement of two variables (x and y) which can be either true or false (the equation is satisfied or not).

Since your equation has two variables, its graph is a collection of points in the plane. I'm not familiar with the particular software you're using, but it's often a pain to graph equations like this, because it's simply harder (computationally speaking) to graph than a function. You have to iterate over every pixel, take its coordinates as x and y, and then evaluated the expression. If the expression is true, you plot the point. Otherwise, you leave it blank.
 
  • #3
Maybe try 2d but in polar...
Looks like cartesian coords needs y=function of x
noting samples on http://www.mathgv.com/
 

1. What is an implicit function?

An implicit function is a mathematical equation in which the dependent variable is not explicitly written in terms of the independent variable. This means that the relationship between the two variables is not easily seen or expressed in a simple form. For example, the equation x^2 + y^2 = 25 is an implicit function because it does not explicitly state the relationship between x and y.

2. Why is graphing implicit functions important?

Graphing implicit functions allows us to visualize the relationship between two variables in a more complex equation. It can help us understand the behavior of the function and identify important points such as intercepts, maxima, or minima. This can be particularly useful in fields such as physics and engineering where complex relationships between variables are common.

3. How do you graph an implicit function?

To graph an implicit function, we can use a graphing calculator or software that can plot implicit equations. Alternatively, we can manipulate the equation to make the dependent variable explicit and then plot it as a normal function. For example, in the equation x^2 + y^2 = 25, we can solve for y to get y = ±√(25-x^2) and then plot the two resulting functions.

4. What are some common challenges when graphing implicit functions?

One common challenge when graphing implicit functions is that the resulting graph may not be a function. This means that there may be more than one y-value for a given x-value. Another challenge is that the graph may not be easily recognizable or may appear distorted due to the complex nature of the equation. It is also important to choose an appropriate range for the x and y axes to accurately represent the behavior of the function.

5. How can understanding implicit functions be useful in real life?

Understanding implicit functions can be useful in many real-life scenarios. For example, in economics, implicit functions can be used to represent the relationship between supply and demand. In physics, implicit functions can help us understand the motion of objects under the influence of multiple variables. In engineering, implicit functions can be used to model complex systems and predict their behavior. Overall, understanding implicit functions can help us make more accurate predictions and decisions in various fields.

Similar threads

  • Calculus
Replies
16
Views
2K
Replies
2
Views
2K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
3
Views
140
  • Calculus
Replies
8
Views
1K
Replies
1
Views
3K
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
710
Replies
2
Views
1K
Replies
3
Views
856
Back
Top