# inverse square root

This topic is 4319 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

i've read this ( http://www.math.purdue.edu/~clomont/Math/Papers/2003/InvSqrt.pdf ) article a few times now but a still confuses fuses me could someone please explain it to me?

##### Share on other sites
What specific part are you struggling with?

##### Share on other sites
"The true exponent e = E − 127 is odd, say e = 2d + 1, d an integer.
The bits representing the initial guess give the new exponent"

after that i seem to start getting confused with what hes doing.

##### Share on other sites
Could you write down a representation of a floating point number in the registry? That article was somehow harder to read. He wrote it in scientifical style that gets in the way.

Try to do some example calculation, for example 1/sqrt(2) or 1/sqrt(4)

##### Share on other sites
the main thing that confuses my is d the d variable what does it mean where does it come from?

##### Share on other sites
a = 2*b + 1 guarantees the "a" would be odd. (b is an integer)

He just used a "d" instead of a "b".

1. 1
2. 2
3. 3
4. 4
frob
11
5. 5

• 10
• 16
• 13
• 20
• 12
• ### Forum Statistics

• Total Topics
632173
• Total Posts
3004579

×