On Sunday, 6 August 2017 at 23:33:26 UTC, greatsam4sure wrote:

import std.math; import std.stdio;## Advertising

cos(90*PI/180) = -2.7e-20 instead of zero. I will appreciateany help. thanks in advance.tan(90*PI/180) = -3.689e+19 instead of infinity. What is thebest way to use this module

`That's just floating point maths for you. You're not putting`

`exactly pi/2 into cos, just a good floating point approximation.`

`What you're getting out isn't exactly 0, either, just a good`

`floating point approximation. (-2.7e-20 is really, really small.)`

`Here's a good talk from DConf 2016:`

`https://www.youtube.com/watch?v=97bxjeP3LzY`

`If you need exact maths, you'll need a symbolic manipulation`

`library (never used one in D, but there was a discussion recently`

`https://forum.dlang.org/thread/ghihookwgzxculshi...@forum.dlang.org). You don't need this for most practical applications, though.`