PDA

View Full Version : Help finding x


Matrix
Nov15-03, 11:48 AM
Hi, I am having trouble finding x for the following exquation:
2x=16-3/4 * sqrt(2)

Any help on solving it would be much apprecitated.

dduardo
Nov15-03, 11:52 AM
why don't you use logs.

2^x = 16^(-3/4) * sqrt(2)

x*ln(2) = ln(16^(-3/4) * sqrt(2) )

x = ln(16^(-3/4) * sqrt(2) ) / ln(2)

jcsd
Nov15-03, 11:56 AM
reduce it further to:

x = -2.5

dduardo
Nov15-03, 12:00 PM
jcsd, your i see you changed your reduction. The previous one was obviously wrong.

Matrix
Nov15-03, 12:02 PM
Is it possible to find x not using logs?

jcsd
Nov15-03, 12:06 PM
Duardo: No, it was perfectly correct.

dduardo
Nov15-03, 12:11 PM
Originally posted by Matrix
Is it possible to find x not using logs?

yes.

you can convert 16 to a base 2

16^(-3/4) = (2^4)^(-3/4) = 2^(-3)

therefore

2^x = 2^(-3) * 2^(1/2)

2^x = 2^(-5/2)

x = -2.5

Chrono
Nov16-03, 10:26 PM
This is probably off topic, but don't you just love logs?