1. Logarithm proofs

Can anyone help with these proofs?

Prove the following formulas for changing from one base to another:
a) log_b x = (log_b a)(log_a x)

b) log_b x = (log_a x)/(log_a b)

Thank so much

2. Originally Posted by Percent09
Can anyone help with these proofs?

Prove the following formulas for changing from one base to another:
a) log_b x = (log_b a)(log_a x)

b) log_b x = (log_a x)/(log_a b)

Thank so much
Log_a x = P
log_b x = Q
log_b a = R

A^P = b^Q = x

(b^R)^P = b^Q
b^RP = b^Q
RP = Q
P = Q/R

log_a x = (log_b x / log_b a)

Just modify it to suit your question.

3. I cant seem to find (a) in my maths book...

Could you just double check your post?