# evaluating logs

• May 11th 2010, 04:01 PM
tmas
evaluating logs
i can't seem to get the right answer for this one..

log(base 2) 8root2
(sorry i don't know how to show this on the computer)

the answer in the back of the book is 7/2 but i am getting 3/2
what am i missing?

2^x = 8root2
2^x = 8^1/2
2^x = (2^3)^1/2
2^x = 2^3/2
x=3/2
• May 11th 2010, 04:57 PM
skeeter
Quote:

Originally Posted by tmas
i can't seem to get the right answer for this one..

log(base 2) 8root2
(sorry i don't know how to show this on the computer)

the answer in the back of the book is 7/2 but i am getting 3/2
what am i missing?

2^x = 8root2
2^x = 8^1/2
2^x = (2^3)^1/2
2^x = 2^3/2
x=3/2

$\log_2(8\sqrt{2}) = \log_2(8) + \log_2(\sqrt{2}) = 3 + \frac{1}{2}$