Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**MathsIsFun**- Replies: 2

A new Calculus page: Solids of Revolution by Disks and Washers

Let me know if you find anything I should change before I release it on the website.

Also any comments or suggestions welcome.

Good point, will see what I can do.

Frame it!

I am also trying to think how to use the mouse to interact with the drawing process.

bobbym wrote:

Can you provide the settings to generate the 5 examples?

Well... I kinda just played around, took a screenshot, played some more, moved on.

I recall the first one was the ellipse preset with a "radius change" of something like 0.1.

The "three rings" had a basic setting like 80,1 80,-2 with a 3rd circle like 80,0.01 but I can't recall exactly.

Where is everyone's artwork?

**MathsIsFun**- Replies: 25

New version of Spiral Artist

The "Expert" button lets you control how the radius and speed change over time.

Radius changes by a factor of (1+change/1000) and can make nice effects

Speed changes by adding change/1000 but I haven't had luck making it do anything cool

Let me know if you have any ideas on making it better!

Post any cool art you make.

Thanks everyone!

I will check out IE (why is it always the exception?)

**MathsIsFun**- Replies: 4

Graph functions of the style f(x,y): 3D Function Grapher

Let me know of any interesting functions you find!

(Also let me know of any bugs/suggestions/comments)

Thanks everyone!

I have also heard "day", so they say "day-f day-x" but that doesn't seem common.

**MathsIsFun**- Replies: 14

A new page: Partial Derivatives

Comments / suggestions welcome.

Hi iamaditya, very nice to hear you like the Calculus material.

I hope to add more Calculus one day, but over the last year or so I have added some Physics pages and am now going though the site updating the graphics. As well I am working with two translators creating a Chinese version of the site!

Y'all confuseded me.

Fixed.

Updated: Mrs Goodsworthys Hats Puzzle - Solution

Yes? No?

Good work!

How would you like the solution worded? And credited?

Maybe an all-text version of "edit" would do the job. If I get some free time I will work on it

Good news!

I have just rebuilt the indexes, maybe that will help.

bob bundy wrote:

Hi MathsIsFun,

This page looks excellent to me. Had to cover a physics lesson once, so, instead of copying from books, I got out the Van de Graaff generator. The effect on washed, fine hair is 'shocking!'.

Bob

Pics please

bobbym wrote:

It might take an individual electron more than a month to make the trip due to innumerable collisions.

I should mention that!

**MathsIsFun**- Replies: 10

A new page: Electricity

Please check it over for accuracy, etc!

Compuhigh.com have asked that we remove this topic "in order to ameliorate the harm to later students who may find the question and answer in an internet search".

I have responded to them "I am awaiting permission from two forum members ... seems a shame as the student was very engaged in the process and learned a lot with members help, as would others visiting the page. There are likely to be many places on the internet (facebook, reddit, etc) where your students will find answers to previous questions, it seems easier to simply change your questions (even a little) every year."

Ignoring many arguments (and a heavy heart), it simply seems like a nice gesture to Compuhigh to remove it.

With your permission anonimnystefy and bob?

Thanks everyone!

I will leave the page as it is until I can think of a way to simplify it without straying into "y=2x+3 becomes y=(x-3)/2" territory.

The "graphing calculator" reasoning might be why Wolfram (ie Mathematica) uses f-¹(x)

Thanks Guys!

I found Wolfram uses f-¹(x): http://mathworld.wolfram.com/InverseFunction.html

It would be nice to simplify the page to f-¹(x) ... but in the intro I say "So the inverse of: 2x+3 is: (y-3)/2" and that does not sit well with using f-¹(x)

Nor with the table of inverses as ganesh mentions.

**MathsIsFun**- Replies: 10

On this page: Inverse Functions

I have f(x) becoming f-¹(y)

But a reader has suggested it should be f-¹(x)

It would certainly be simpler not swapping y for x. What is correct do you think?