Re: trying to understand why I get 2.2204e-16 rather than 0

[Dmitri A. Sergatskov]

On Wed, Aug 3, 2016 at 7:41 PM, naryana.shankara <address@hidden> wrote:

If I enter cot (pi/4)-1 I get 2.2204e-16
>From my trig days I remember cot (pi/4) is 1 and 1-1 is 0
Octave also confirms cot (pi/4) is 1 and 1-1 is 0

octave:6> format hex
octave:7> 1
ans = 3ff0000000000000
octave:8> cot(pi/4)

​​

ans = 3ff0000000000001

 

so why does Octave spit out 2.2204e-16 when cot(pi/4)-1 is entered?

https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
 

​Dmitri.
--
​