How do you show that the slope of #a^y=b^x# is #log_a b#?

1 Answer
Dec 18, 2015

I used some properties of logs:

Explanation:

Let us try to isolate #y# first by taking the #ln# of both sides:
#lna^y=lnb^x#
use the fact that:
#logx^y=ylogx#
so that you get:
#yln(a)=xln(b)#
or rearranging:
#y=ln(b)/ln(a)x#Then
we can use the change of base in reverse to get:
#log_a(b)=ln(b)/ln(a)#
and we get:
#y=log_a(b)x#
which is in the form #y=mx#
with #m=log_a(b)="constant"="Slope"#