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What is the domain of the function y=ln(12-4x/5)

User Fes
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1 Answer

1 vote

Answer:

x < 15

Explanation:

Important: The domain of y = ln x is (0, ∞).

Thus, to answer this question, we set the argument 12 - 4x/5 = to 0 and solve for x:

12 - 4x/5 = 0,or 12 = 4x/5.

Mult. both sides by 5, we clear out the fractions: 60 = 4x.

Solving for x: x = 60/4 = 15

Supposing we let x = 14, is 12 - 4x/5 = to 0

Choose a test number based upon this 15: 14 is smaller and 16 is larger.

Let x = 14. Is 12 - 4x/5 ≥ 0, as it must be?

Is 12 - 4(14)/5 ≥ 0?

Is 60 - 56 ≥ 0? Yes. Thus, the domain of the given function includes all real numbers less than 15.

User Karamjit
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