# Talk:Involute

### From Math Images

Team,

- Please read the page again and let me know which parts need more explanation.
- When you leave comments, would you please use a different color from black so that I know it's new comments please? I'll change them back to black later. Thanks!

## Contents |

# General Comments

# Basic Description

An involute of a circle can be obtained by rolling a line around the circle

- in a special way. -- CHECK

Involute is also known as evolvent.

- This is pretty obscure, at least I only see this in dictionaries, and not in common use. Maybe ditch it? -- CHECK

To Draw an Involute

- It would be great to have this so you could state a step, then click something to animate, etc. (This is done in one big glop in your next section). -- CHECK

This error gets smaller as we construct more tangent lines that they are near enough together.

- you don't way the "they" in that sentence. -- CHECK

Involute is also the roulette ...

- You want: The involute is also ... --CHECK

What's wrong with this sentence?

- He invented and built the world's first pendulum clock in 1956 --CHECK

# More Mathematical Explanation

This property holds true for all other types of curves as well

- as we shall soon see. -- CHECK

Do we want Properties and Formulas under More Mathematical Explanation, or could they be just small subsections? (would this be allowed??) -- I think these two sections are actually more mathematical than the examples and I should hide them. I'll see what other people think about this.

I think the various examples of involutes should all be hidden with just their names showing. Similarly, just General Formula showing and derivation hidden. -- CHECK

# Why Interesting

From the present: please explain pitch-circle and base circle. Picture is nice but may not be quite enough. --CHECK

One of the most commonly used gearing system today is the involute gear.

- involute gear in boldface or italics --CHECK

# Comments from the Past

### Gene 6/28

Actually, Tanya, both Mathworld and Wikipedia have pretty accessible looking articles on involutes, so maybe we should link to them when needed.

### Tanya 06/23

I'm having issues on how to go about the involute. I will try to find some more about it in textbooks, but I am not sure if there is a tangent involved at all, or how the length of the line relates to the curve, etc. Any insight is welcome.