Talk:Cardioid: Difference between revisions

Content deleted Content added

Inline

Revision as of 10:18, 11 March 2009

Mathematics Start‑class Low‑priority

	Mathematics portal This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics articles
Start	This article has been rated as Start-class on Wikipedia's content assessment scale.
Low	This article has been rated as Low-priority on the project's priority scale.

Move the graph to the top?

- seconded

Huh?? Why move a chunk of page content off to a subpage? Dysprosia 01:27, 19 May 2005 (UTC)[reply]

See Wikipedia:WikiProject Mathematics/Proofs#Cardioid. -- Jitse Niesen 11:33, 19 May 2005 (UTC)[reply]

Pear?

I'm no geometer, but it looks like the cross-section of a globe tomato to me.

It's a butt... —Preceding unsigned comment added by 84.238.88.87 (talk) 08:49, 12 January 2008 (UTC)[reply]

Images

I do not understand how the images can be understood - what are x and y? --Abdull 16:11, 23 May 2006 (UTC)[reply]

The Equations section describes x and y in terms of theta. --Jevon 20:39, 25 May 2006 (UTC)[reply]

The equations express the rectangular coordinates of the curve, x and y, in terms of a parameter theta. That is, for each value of theta, compute x(theta) and y(theta), and plot the point (x,y) measured x units to the right of the y axis, and y units above the x axis (other direction for negatives). The set of all such points makes the curve shown in the image. So, x and y are just numbers to describe the location of a point on a curve. Dicklyon 22:25, 5 June 2006 (UTC)[reply]

The other way to understand the images is to ignore x and y, and just look at rho (radius) and theta. At each angle theta measured from the positive x axis, compute the radius rho and put a point that far from the origin. At 180 degrees, the formula 1+cos(theta) gives zero, so you get a point at the origin, which is the cusp. By displacing theta, or using sin instead of cosine, the whole picture just rotates around that cusp. Dicklyon 22:29, 5 June 2006 (UTC)[reply]

IMHO should be merged with into Heart (Symbol)

IMHO should be merged with into Heart (Symbol) --Wulf 03:17, 5 June 2006 (UTC)[reply]

Absolutely not. Read the article. The two shapes are not the same. Dysprosia 03:23, 5 June 2006 (UTC)[reply]

That's almost as bad as calling a trapezoid a squashed square. --ssd 07:14, 26 August 2007 (UTC)[reply]

If you want to know r=4*sin^-1((sin(O/2)^(3/2))) graphs a better "love heart" shape [Matthew Schimpf 7:15 11 March 2009] —Preceding unsigned comment added by 121.221.2.176 (talk) 10:17, 11 March 2009 (UTC)[reply]

The caustic seen at the bottom of a coffee cup

It's a nephroid. I have solved this problem. —Preceding unsigned comment added by 84.2.80.109 (talk) 11:49, 29 October 2007 (UTC)[reply]

As the article states, it may be a cardioid, and it may be a nephroid. It depends on the angle of the light rays relative to the bottom of the cup. Cheers, Doctormatt 17:58, 29 October 2007 (UTC)[reply]

@@ Line 38: / Line 38: @@
 That's almost as bad as calling a [[trapezoid]] a squashed square. --[[User:Ssd|ssd]] 07:14, 26 August 2007 (UTC)
-If you want to know r=4*sin<sup>-1</sup>((sin(O/2)<sup>(3/2)</sup>)) graphs a better "love heart" shape [Matthew Schimpf 7:15 11 March 2009]
+If you want to know r=4*sin<sup>-1</sup>((sin(O/2)<sup>(3/2)</sup>)) graphs a better "love heart" shape [Matthew Schimpf 7:15 11 March 2009]  <span style="font-size: smaller;" class="autosigned">—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/121.221.2.176|121.221.2.176]] ([[User talk:121.221.2.176|talk]]) 10:17, 11 March 2009 (UTC)</span><!-- Template:UnsignedIP --> <!--Autosigned by SineBot-->
 == The caustic seen at the bottom of a coffee cup ==