Question #c4bbb

1 Answer
Nov 5, 2016

a=b and a=1/b^2

Explanation:

Given log_ab^2 = c and log_b a=c-1

So

log_ab^2-1 = c-1= log_b a

=>log_ab^2-1 =1/log_a b

=>(2log_ab-1) log_a b=1

=>2(log_ab)^2- log_a b-1=0

taking log_a b=x we get

2x^2-x-1=0

=>2x^2-2x+x-1=0

=>2x(x-1)+1(x-1)=0

=>(x-1)(2x+1)=0

So when x-1=0 =>x=1

=>log_a b=1=log_a a

=>a=b

Again when 2x+1=0

=>2log_a b+1=0

=>log_a b^2=-1

=>b^2=a^-1=1/a

=>a=1/b^2