Does a circle have a constant rate of change of it self that defines

In summary, the conversation discusses the concept of a circle having a constant rate of change that defines it, and whether or not it is possible to characterize a circle as a "curling" of a line. The differential geometry perspective is mentioned, and it is stated that a circle can be defined in polar coordinates by having a constant radius. The equation for a circle is also mentioned.
  • #1
MotoPayton
96
0
Does a circle have a constant rate of change of it self that defines it as a circle.
I have never heard of such a thing but I am curious. It must right??

Since every circle is the same no matter the radius(the arch will change by some constant amount per radian)

If that doesn't make sense.. I am asking by how much does some line segment need to fold onto itself to form a perfect circle. What will be the rate of change of that line segment to form a perfect circle and with respect to what variable??
 
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  • #2


I'm not quite sure what you're asking, but the curvature of a circle of radius r is the constant r-1.
 
  • #3


A differential geometry perspective.

Sooo... I'm not entirely sure if this will help, but I think that the answer to the "constant speed question" is not necesarily. Idealy we could make the circle be traced out at constant speed.

Here is how i think of it.
C:[0,1] --> S1
S1 will be the circle as a subset of the plane.
We can make
C=(cos(t),sin(t))

this takes the first point of the line, and then puts it at the (1,0) point on the circle. Every other point is then curled to follow the tangent vector (-sin(t), cos(t) ).
that gives us a "constant rate".

Now it may be shown that there are probably infinitely many other paramaterizations of a circle, and some analytic geometry will show that you could define circles that don't have constant speed paramaterizations, in fact you could paramaterize it to not be "smooth".

I hope this helps, but I now think maybe you were asking if there is a way to characterize the circle as a "curling" of the line?
 
  • #4


MotoPayton said:
Does a circle have a constant rate of change of it self that defines it as a circle.
I have never heard of such a thing but I am curious. It must right??

Since every circle is the same no matter the radius(the arch will change by some constant amount per radian)

If that doesn't make sense.. I am asking by how much does some line segment need to fold onto itself to form a perfect circle. What will be the rate of change of that line segment to form a perfect circle and with respect to what variable??

You can define a circle in polar coordinates by

[tex]\frac{dr(\theta)}{d\theta} = 0[/tex]
with [itex]r(\theta_0) = R \neq 0 [/itex]. i.e., the radius of the curve does not change with theta, and you know that r for some value of theta is a non-zero number.
 
  • #5


To get the equation of the circle, requirements are radius and center point right..??
(x-h)^2-(y-k)^2=r^2
 

1. What is the definition of rate of change?

The rate of change is a measure of how much a quantity is changing over a specific period of time. It is typically represented by the symbol "m" and is calculated by dividing the change in the dependent variable by the change in the independent variable.

2. What is a constant rate of change?

A constant rate of change refers to a situation where the rate of change remains the same throughout the entire change in the independent variable. This means that the dependent variable is changing at a constant and consistent rate over time.

3. Can a circle have a constant rate of change?

No, a circle does not have a constant rate of change. This is because the distance around a circle (circumference) changes at a different rate than the distance across the circle (diameter). As the circle gets larger, the circumference increases at a faster rate than the diameter.

4. How is rate of change related to circles?

Rate of change is not directly related to circles, as circles do not have a constant rate of change. However, the concept of rate of change can be applied to circles in terms of their linear dimensions (such as diameter and circumference) or in terms of their angles and radians.

5. Why is it important to understand the rate of change of circles?

Understanding the rate of change of circles can be useful in various fields such as geometry, physics, and engineering. It can help in calculating and predicting the behavior of circular objects and their components, as well as in designing and analyzing circular structures and systems.

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