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What are the domain and range of f (x) = log (x 6) minus 4?

User JuZDePeche
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1 Answer

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16 votes

Answer:

We will see that the domain of the function is:

D: x ∈ R

How to find the domain of a function?

To find the domain of a function, we start by assuming that it is the set of all real numbers, and then we remove the problematic points.

In this case, we have a logarithm, and as you may remember, we can only evaluate the logarithm in positive values, so we need to remove all the values of x such that:

x + 6 ≤ 0

Solving for x, we get:

x ≤ -6

So the only values of x allowed are the ones that make the next inequality true:

x > -6.

Thus we can write the domain as:

D x ∈ R

Where the second part, x ∈ R, is usually ignored, as we assume that x is a real number unless we specify that it is not, but just for completion, I wrote it.

User Gaurav Thantry
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