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Given f(x)=1/x-2 and g(x)=square root of x+2, what is the domain of f (g(x))?.A. ℝB. [–2, ∞)C. [–2, 2) ∪ (2, ∞)D. (–∞, 2) ∪ (2, ∞)

User Ryan Grove
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1 Answer

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we have the functions


\begin{gathered} f(x)=(1)/(x-2) \\ \\ g(x)=√(x+2) \end{gathered}

Find out f(g(x))


f\mleft(g\mleft(x\mright)\mright)=(1)/(√(x+2)-2)

Remember that

The radicand must be greater than or equal to zero and the denominator cannot be equal to zero

so

step 1

Solve the inequality


\begin{gathered} x+2\ge0 \\ x\operatorname{\ge}-2 \end{gathered}

the solution to the first inequality is the interval [-2, infinite)

step 2

Solve the equation


\begin{gathered} √(x+2)-2\\e0 \\ √(x+2)\operatorname{\\e}2 \\ therefore \\ x\operatorname{\\e}2 \end{gathered}

The domain is the interval

[–2, 2) ∪ (2, ∞)

The answer is the option C

User Lkopo
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