# Cos is not returning 0 for 90 degrees or PI/2

This topic is 2069 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

.1 in binary is 0.0001100110011001100110011001100110011001100110011... A repeating fraction. Stop after any finite number of bits and you don't get an exact representation.

##### Share on other sites

.1 in binary is 0.0001100110011001100110011001100110011001100110011... A repeating fraction. Stop after any finite number of bits and you don't get an exact representation.

Thank you for filling me in. Good to know!

##### Share on other sites
remember that float can provide certian exactness to computations against some extend. so if you need to get to very low extends, you should linear reduce those extends..... if you want to cumpute angle of earth against its eclipse (the plane that earths orbits the sun, thus 0 degrees exactly), you would have to provide sin (0)... you will never continue with this result unless you apply special data type or special routine of fractionizing the linear space to linear space power.

if you used the minimal epsilon you would end up with earth quite missing its real place.

##### Share on other sites

remember that float can provide certian exactness to computations against some extend. so if you need to get to very low extends, you should linear reduce those extends..... if you want to cumpute angle of earth against its eclipse (the plane that earths orbits the sun, thus 0 degrees exactly), you would have to provide sin (0)... you will never continue with this result unless you apply special data type or special routine of fractionizing the linear space to linear space power.

if you used the minimal epsilon you would end up with earth quite missing its real place.

I didn't get any of that. What's an "extend"? And what's wrong with computing sin(0)? What on Earth is "fractionizing the linear space to linear space power"?

##### Share on other sites

What on Earth is "fractionizing the linear space to linear space power"?

Good question. Think about amount of angles of earths sun orbit to its eclipse(plane between earth and sun).
Perfect 0.0.
But you do not never not know exact number, whatever it seems exact...... So "if eclipse of earth is identical to eclipse of earth", it may be volating some amount, hard to measure exact. Numbers can contain many information, the most exponsive information is information about the angle (never ending)

##### Share on other sites
I'm not sure what exactly you're on about, but I'm pretty sure it's not on topic.

Let's keep this thread to the point, shall we?

##### Share on other sites

[quote name='alvaro' timestamp='1337899226' post='4943035']
What on Earth is "fractionizing the linear space to linear space power"?

Good question. Think about amount of angles of earths sun orbit to its eclipse(plane between earth and sun).
Perfect 0.0.
But you do not never not know exact number, whatever it seems exact...... So "if eclipse of earth is identical to eclipse of earth", it may be volating some amount, hard to measure exact. Numbers can contain many information, the most exponsive information is information about the angle (never ending)
[/quote]
No offense, but... YOU'RE NOT MAKING ANY SENSE.

I wrote this while ApochPiQ was posting... I'm done here. Edited by Cornstalks

##### Share on other sites
off topic? OP wants to know and you are off topic? maybe I was not exact, ok, but I do not have right to post my 2 cents then? What restrictive policy is that for OPs to find out their solutions?

##### Share on other sites
Dude, the question was solved - including with input from a notable expert - and there's nothing left to figure out. And now you're talking about eclipses (or, presumably, ecliptics which are hardly the same thing).

I have no idea how you consider that on topic.

##### Share on other sites

This topic is 2069 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

This topic is now closed to further replies.