log subscript2 8?

Question

how would i work this?

Answer 1

3

It is the exponent to be used on the number 2 (the base) to get you the number 8.

Answer 2

This is saying "log base 2 of 8 equals y". "Y" being the variable you do not know.

Change this to an exponential equation. Here's how to go from exponential to logarithmic.

log_b(x) = a (this is saying log BASE b of x is a)
b^a = x

So, let's look at your log and find the variables.

log_2(8) = y

In your eqation, b = 2, x = 8, and a =y.

So, put it into the exponential equation.

b^a = x
2^y = 8

This is saying "2 to what power equals 8"?

If you do not already know the answer, change 8 to a power with a base 2.

2^y = 2^3

Now, since the bases are the same, the exponents must be equal.

y = 3

Answer 3

Let log(base 2)8 = x. Then 2^x = 8. Since 2^3 = 8 then x = 3 which is the answer to your question.

Answer 4

is it 8 log 2