SOLUTION: find the domain of the following function in interval notation : f(x)= 3√ln(x/2)

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Question 639079: find the domain of the following function in interval notation :
f(x)= 3√ln(x/2)

Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
First of all, the argument of any logarithm must be positive. So
x%2F2+%3E+0
which resolves to
x+%3E+0

Second, the radicand of a square root must not be negative. So:
ln%28x%2F2%29+%3E=+0
You might be able to logically dtermine from this that
x%2F2+%3E=+1
After all, an exponent of 0 results in 1. So any argument of 1 or greater will have an exponent greater than 0. If you can't see this then we have to solve ln%28x%2F2%29+%3E=+0. We solve the inequality by rewriting it in exponential form:
x%2F2+%3E=+e%5E0
Since any non-zero number, including e, to the zero power is 1 this becomes:
x%2F2+%3E=+1
Multiplying by 2 we get:
x+%3E=+2

From the fact that the argument of the log had to be positive we found that
x+%3E+0
must be true. From the fact that radicands of square roots must bot be negative we found that
x+%3E=+2
must be true. Since both of these must be true, the domain must be
x+%3E=+2
(since any number greater than or equal to 2 must also be greater than 0).