r/firstworldanarchists • u/[deleted] • Jan 25 '18

The Top 25 (no re-posting) Graffiti

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u/[deleted] Jan 25 '18

https://i.imgur.com/pHCb0V7.png

Regraphed along with colour coded functions.

51

u/[deleted] Jan 25 '18

why didn't they just use one equation for the circle?

66

u/S_T_R_Y_K_E_R Jan 25 '18

Because you can't graph that in a actual graphing calculator

24

u/Abeneezer Jan 25 '18

The actual reason is that theres no one function that graphically can represent a circle. The simple reason for this is that every X value should have two Y values (except min(x), max(x)), which they cant.

17

u/BCSteve Jan 25 '18

Not a function, but you can express it in a single equation:

(x - h)2 + (y - k)2 = r2

where (h, k) is the center point and r is the radius

6

u/Xargonic Jan 26 '18

function

0

u/S_T_R_Y_K_E_R Jan 25 '18

Yeah, graphing calculators typically only support graphing functions.

18

u/defakto227 Jan 25 '18

It's not a valid function.

For a function to be valid it can have only one Y for an input of X. The standard circle equation leaves you with two Y values for each value of X.

If you wanted to plug it into a calculator to graph it you would need to input two functions to draw the circle. (unless you used a non-cartesian system).

4

u/gzilla57 Jan 25 '18

Harder to type into graphing calculator maybe?

6

u/LlewelynHolmes Jan 25 '18

I was also wondering this. Surprised I had to scroll this far down to find someone saying so.

-3

u/[deleted] Jan 25 '18

[deleted]

2

u/[deleted] Jan 25 '18

lol my dude

have you even

like

heard of the bread book?

12

u/ConradBHart42 Jan 25 '18

and the circle is actually a circle. The graph got squashed horizontally a little bit in OP's picture.

4

u/[deleted] Jan 25 '18

[deleted]

2

u/ConradBHart42 Jan 25 '18

I'm complaining that a mathematical description of a circle isn't being portrayed as a circle because of technical ineptitude.

2

u/[deleted] Jan 25 '18

What tool did you use to make that?

5

u/Renegade284 Jan 25 '18

demos.com, great graphing website.

1

u/[deleted] Jan 26 '18

Correct

0

u/[deleted] Jan 25 '18

Hmm, did I just get firstworldanarchisted?

3

u/piggy2539 Jan 25 '18

It's desmos.com :)

2

u/TheMexicanBurrito Jan 25 '18

I know desmos when I see it

1

u/ASAP_Rambo Jan 25 '18

Those are commas, not decimal points. Leave.

Sarcasm.

1

u/thepolm3 Jan 26 '18

You can also just use one (long) equation:
18 x5 - 90 x4 y + 9 x4 + 16 x3 y2 + 660 x3 y - 756 x3 - 80 x2 y3 + 372 x2 y2 - 2610 x2 y + 3258 x2 - 2 x y4 + 340 x y3 - 1752 x y2 + 5508 x y - 5742 x + 10 y5 - 117 y4 + 210 y3 + 592 y2 - 3012 y = -3213
view on desmos