Fooling the CASIO ClassWiz fx-991LA X

[Gerson W. Barbosa]

\(\frac{\rm{e}^{\frac{23}{4}-{\left({\left(\frac{40}{211}\right)}^{2}+100\right)}^{-2}}}{100}\)


\[\rm{\pi}\]

;-)

[lrdheat]

Great approximation! Fooled my fx-991EX as well. My Prime shows the approximation departs from pi by <1 part in 10^-12.

[lrdheat]

In double precision mode, the approximation varies from pi by~8.21*10^-14 on my WP 34S

[Paul Dale]

Very nice approximation correct to fourteen digits!

Code:

3.1415926535897111461
3.1415926535897932384
               ^^^^^^

The second is π.


Pauli

[Gerson W. Barbosa]

(05-15-2017 01:23 AM)lrdheat Wrote:  Great approximation! Fooled my fx-991EX as well. My Prime shows the approximation departs from pi by <1 part in 10^-12.

This will almost fit the fx-991ES screen:


\(\frac{1501}{150115}\rm{e}^{\frac{23}{4}}\)

No fooling this time, though:

\(3.141592653\)

"http://wes.casio.com/math/index.php?q=I-273A+U-0005000CC3F8+M-C10000AD00+S-090410100000100E1210B00051DA+R-0314159265289162010000000000000000000000+E-C81D1A313530311B1A3135303131351B1E721AC81D1A32331B1A341B1E1B"

[Gerson W. Barbosa]

(05-15-2017 01:33 AM)Paul Dale Wrote:  Very nice approximation correct to fourteen digits!

Code:

3.1415926535897111461
3.1415926535897932384
               ^^^^^^

The second is π.


Pauli

Notice \(ln(100\pi)=5.749900072\) is close to 23/4 (but not close enough).

I like the following better, found with help of HP-32SII solver:

\(\ln\left(\frac{16\ln\left(878\right)}{\ln\left(16\ln\left(878\right)\right)}\r​ight)\)

"http://wes.casio.com/math/index.php?q=I-273A+U-0005000CC3F8+M-C10000AD00+S-090410100000100E1210B00051DA+R-0314159265376844010000000000000000000000+E-75C81D1A313675383738D01B1A75313675383738D0D01B1ED0"





Five digits reused once yielding 10 correct digits.

Gerson.

Edited. Trouble with LATEX here on Chrome, so I've added a picture. Also, I cannot link the CASIO WES website here, the address between quotes above.