std.math module

[Nicholas Wilson via Digitalmars-d-learn]

On Sunday, 6 August 2017 at 23:33:26 UTC, greatsam4sure wrote:
> import std.math;
> import std.stdio;
>
> cos(90*PI/180) = -2.7e-20 instead of zero. I will appreciate 
> any help. thanks in advance.
>
> tan(90*PI/180) = -3.689e+19 instead of infinity. What is the 
> best way to use this module

in addition to what sarn said, tan(3pi/4) is a pole, not 
infinity. the mean of the left and right hand limits is 0