# Logarithmic Equation - Pretty Confused

1. Oct 18, 2007

### coolkid800

this is what I'm having trouble with:

Let r = log6 17, s = log4 17, t = log6 4.

Write the following expressions in terms of r, s, and/or t. The change of base formula may be helpful in finding some of these logarithms.

log16 17 =

http://www.webassign.net/www31/symImages/6/a/1835a244d7715d29ef2d1f41e45aff.gif

log16 17(6^(log36 4) =

http://www.webassign.net/www31/symImages/d/4/9b6ebc66e4a9ccb204874138ac34c3.gif

Plz help!

Last edited: Oct 18, 2007
2. Oct 18, 2007

### cristo

Staff Emeritus
Well, you've been given a hint. What are the "change of base" formulae?

3. Oct 18, 2007

### coolkid800

lol I don't know, I tried looking in my textbook and I couldn't find anything!!

4. Oct 18, 2007

### Helical

5. Oct 18, 2007

### coolkid800

i dont understand how i got the first one wrong, isnt it supposed to be r/2t

6. Oct 18, 2007

### Feldoh

Change $$log_{16}17$$ to base 4.

7. Oct 18, 2007

### coolkid800

okay the first one that i asked u guys, the answer is s/2

apparently i thought i got the last one right, but it was wrong, i put s(6^t/2)

but it was s+.5, anybody kno why?!?

8. Oct 19, 2007

### cristo

Staff Emeritus
Have you looked at the change of base formula provided in the link above? For the first question, follow the hint by Feldoh, and use the change of base formula; so, $$\log_{16} 17=\frac{\log_4 17}{\log_4 16}$$. Can you continue?

Incidentally, you should post in the homework forums in future.