given f(x)=log[4]x, then f(8) equals?

Given f(x) = log4 (x)

We need
to find f(8)

We will substitute with x= 8 into the
equation.

==> f(8) = log4
(8)

Now we will rewrite as a
product.

==> g(8) = log4
(2*4)

But we know that log4 2*4 = log4 2 + log4
4

But log4 4 = 1

==>
log4 8 = log4 2 + 1

Now we will rewrite log4 2 = log2 2 /
log2 4 = 1/log2 2^2 = 1/2log2 2 = 1/2

==> log4 8 =
1/2 + 1 = 3/2

Then we conclude that f(8) =
log4 8 = 3/2