If log_ba=1/x and log_a √b =3x^2, show that x =1/6?

3 Answers
Jun 3, 2018

"see explanation"

Explanation:

"using the "color(blue)"law of logarithms"

•color(white)(x)log_b x=nhArrx=b^n

log_b a=1/xrArra=b^(1/x)

log_a b^(1/2)=3x^2rArrb^(1/2)=a^(3x^2)

"substitute "a=b^(1/x)" into "a^(3x^2)

b^(1/2)=(b^(1/x))^(3x^2)=b^(3x)

"we have "b^(1/2)=b^(3x)

3x=1/2

"divide both sides by 3"

x=(1/2)/3=1/6

x=1/6

Explanation:

log_b a=1/x

So

xlog_ba=1

x=1/log_b a

x=log_ab

Now

1/2log_a b=3x^2" " (substituting from log_a b=x)

So

x/2=3x^2

x=6x^2

6x=1

x=1/6 with x !=0

Hence proved.

Jun 3, 2018

We will start the proof

Explanation:

We have
ln(a)/ln(b)=1/x
and

1/2*ln(b)/ln(a)=3x^2
so

ln(a)/ln(b)=1/(6x^2)

using the first equation we get
1/x=1/(6x^2)

multiplying by x^2 we get

x=1/6 for xne 0