Thursday, May 24, 2012

Explaining B-Trees: animated video

video


This video is not owned by me, I just screen casted it and put into video so you can do track by time compared to their flash base which is annoying when you wanted to back track.

This video is taken from http://www.csanimated.com/animation.php?t=B-tree


Using your calculator to validate logarithms with exponents and get result of logarithms

I just stumbled this earlier when I was playing with my calculator and I forgot how to use it, so I remember that logarithms is just a way of a reverse formula of exponents.

So I came up with this solution,

log2(8) = 3

in calculator,
press 8 + press x radical symbol(y) + press 3 = 2

log2(3) = 1.58496250072116

in calculator
press 3 + press x radical symbol(y) + 1.58496250072116 = 2


log4(16) = 4294967296
in calculator
press 4294967296 + press x radical symbol(y) + 16 = 4

So the formula is,

logbase(logarithm number) = result

or

result as the index then radical symbol(logarithm number as the radicand) = base

then,

baseresult = logarithm number


Now to get the result of a logarithm in calculator, you can use natural logarithm. To calculate it,
do,

ex.

ln(16)/ln(2) = 4

which is equivalent to,

log2(16) = 4

another ex.

ln(65536)/ln(4) = 7.99 = 8

which is equivalent to
log4(65536) = 8