A quick precision test

[Paul Dale]

(06-07-2014 11:56 AM)pito Wrote:  In Wolfram Alpha:

Code:

With 120 digits of "precision":

cos(1.57079632679489661923132169163975144`120)

2.098584699687552910487472296153908203143104499314017412671058533991074041716259​78775626172739947883181185207919839... × 10^-36
...

Ahh, the problem seems to be the decimal point limiting the number of significant digits. Adding zeros would increase the number of digits used and hence the correct result.

Expressing the decimal number as a rational yields the result we're looking for:

Code:

cos(157079632679489661923132169163975144/1e35)

- Pauli