Why the trigonometry results are different

9 Ansichten (letzte 30 Tage)
Madhu am 21 Aug. 2014
Beantwortet: Peter Perkins am 22 Aug. 2014
Why there is a difference in the results. in degrees it is showing inf and in radians a different result?
>> a=tan(90)
a =
>> b=tand(90)
b =
>> c=tan(pi/2)
c =

Akzeptierte Antwort

Peter Perkins
Peter Perkins am 22 Aug. 2014
1.6331e+16 is the right answer. Remember that pi/ is irrational. There is no way to represent it in double precision. The tangent of the double precision value pi/2 evaluates to is 1.6331e+16. That's the main reason for the existence of tand -- 90 is exact.

Weitere Antworten (3)

David Sanchez
David Sanchez am 21 Aug. 2014
The different result between tan(90) and tan(pi/2) is obvious.
1.6331e+16 might be considered equal to inf

Iain am 21 Aug. 2014
That's likely just the effect of small numerical errors.
After all, according to matlab,
1E300 + 1 - 1E300 = 0, and
1E300 - 1E300 + 1 = 1

Adam am 21 Aug. 2014
tan is asymptotic at 90 degrees, but pi/2 will not evaluate to the precise equivalent with a numerical estimate of pi so its result will not be precisely on the asymptote


Find more on Trigonometry in Help Center and File Exchange


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by