explain xkcd - User contributions [en]

Talk:217: e to the pi Minus pi

2014-04-23T22:49:26Z

Katavschi:

Asserting that the programmers' algorithms truncated to three decimal digits is an unsupported and unnecessary extrapolation. Most floating-point implementations use binary, not decimal, and 19.999099979 ''looks'' very much like a rounding error in binary floating-point that has accumulated over several operations. [[User:Daddy|Daddy]] ([[User talk:Daddy|talk]]) 12:39, 29 April 2013 (UTC)
:Fixed. [[User:Xhfz|Xhfz]] ([[User talk:Xhfz|talk]]) 22:57, 16 August 2013 (UTC)

The third bullet-point above needs changing... (9^2+(19^2/22))=97.4090909091 which is close to pi to the fourth power, so it should be (as noted in the text) (9^2+(19^2/22))^1/4 [[User:Squirreltape|Squirreltape]] ([[User talk:Squirreltape|talk]]) 19:27, 25 February 2014 (UTC)
:Actually, in-case you didn't notice, it says "∜(9² + 19²/22)", not just the sum on its own. I checked the sum on my calculator, and it is equal to what the page is saying. "∜(9² + 19²/22)" means "4th root of (9^2+19^2/22)" (What the title text is saying), or on Windows Calculator, "(9^2+19^2/22) yroot(4)" (Basically what the sum is saying). So, the 3rd bullet point is correct. --[[User:Katavschi|Katavschi]] ([[User talk:Katavschi|talk]]) 22:48, 23 April 2014 (UTC)

Talk:217: e to the pi Minus pi

2014-04-23T22:48:16Z

Katavschi:

Asserting that the programmers' algorithms truncated to three decimal digits is an unsupported and unnecessary extrapolation. Most floating-point implementations use binary, not decimal, and 19.999099979 ''looks'' very much like a rounding error in binary floating-point that has accumulated over several operations. [[User:Daddy|Daddy]] ([[User talk:Daddy|talk]]) 12:39, 29 April 2013 (UTC)
:Fixed. [[User:Xhfz|Xhfz]] ([[User talk:Xhfz|talk]]) 22:57, 16 August 2013 (UTC)

The third bullet-point above needs changing... (9^2+(19^2/22))=97.4090909091 which is close to pi to the fourth power, so it should be (as noted in the text) (9^2+(19^2/22))^1/4 [[User:Squirreltape|Squirreltape]] ([[User talk:Squirreltape|talk]]) 19:27, 25 February 2014 (UTC)
:Actually, in-case you didn't notice, it says "∜(9² + 19²/22)", not just the sum on its own. I checked the sum on my calculator, and it is equal to what the page is saying. "∜(9² + 19²/22)" means "4th root of (9^2+19^2/22)" (What the title text is saying), or on Windows Calculator, "(9^2+19^2/22) yroot(4)" (Basically what the sum is saying). So, the 3rd bullet point is correct, while you are wrong. --[[User:Katavschi|Katavschi]] ([[User talk:Katavschi|talk]]) 22:48, 23 April 2014 (UTC)