tan(pi/24), what is the correct result?

[Dieter]

(09-05-2016 07:05 PM)Dol Wrote:  How come Windows 7 calculator gets its so wrong?
Also I tried free42 on iOS and it also gets 0.0023 (wrong).
Ill update the initial post with the new values.

There is nothing wrong here.

The tangent of pi/24 degrees is 0,00228463462331349894308299181233...
The tangent of pi/24 radians is 0,131652497587395853471526457409...

The calculators you used were once set to degrees and once to radians. That's it.
And if you set Free42 to ALL display mode instead of FIX 4 you will see the full-precision result instead of just 0,0023. Or simply press the SHOW key.

So just set the correct angular mode and you'll get a correct result.
With all of the mentioned calculators. There's nothing wrong with them at all.

Within working precision, that is. A 10-digit calculator will not evaluate the tangent of pi/24, but of {3,141592654/24 rounded to 10 digits}, i.e. it will calculate tan(0,1308996939) = 0,00284634623 (degrees) resp. 0,1316524976 (radians).

Dieter