Precalculus Examples

$f (x) = \frac{3 x - 2}{\sqrt{4 x + 4}}$

Step 1

Set the radicand in $\sqrt{4 x + 4}$ greater than or equal to $0$ to find where the expression is defined.

$4 x + 4 \geq 0$

Step 2

Solve for $x$ .

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Step 2.1

Subtract $4$ from both sides of the inequality.

$4 x \geq - 4$

Step 2.2

Divide each term in $4 x \geq - 4$ by $4$ and simplify.

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Step 2.2.1

Divide each term in $4 x \geq - 4$ by $4$ .

$\frac{4 x}{4} \geq \frac{- 4}{4}$

Step 2.2.2

Simplify the left side.

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Step 2.2.2.1

Cancel the common factor of $4$ .

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Step 2.2.2.1.1

Cancel the common factor.

$\frac{4 x}{4} \geq \frac{- 4}{4}$

Step 2.2.2.1.2

Divide $x$ by $1$ .

$x \geq \frac{- 4}{4}$

Step 2.2.3

Simplify the right side.

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Step 2.2.3.1

Divide $- 4$ by $4$ .

$x \geq - 1$

Step 3

Set the denominator in $\frac{3 x - 2}{\sqrt{4 x + 4}}$ equal to $0$ to find where the expression is undefined.

$\sqrt{4 x + 4} = 0$

Step 4

Solve for $x$ .

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Step 4.1

To remove the radical on the left side of the equation, square both sides of the equation.

${\sqrt{4 x + 4}}^{2} = 0^{2}$

Step 4.2

Simplify each side of the equation.

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Step 4.2.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{4 x + 4}$ as ${(4 x + 4)}^{\frac{1}{2}}$ .

${({(4 x + 4)}^{\frac{1}{2}})}^{2} = 0^{2}$

Step 4.2.2

Simplify the left side.

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Step 4.2.2.1

Simplify ${({(4 x + 4)}^{\frac{1}{2}})}^{2}$ .

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Step 4.2.2.1.1

Multiply the exponents in ${({(4 x + 4)}^{\frac{1}{2}})}^{2}$ .

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Step 4.2.2.1.1.1

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

${(4 x + 4)}^{\frac{1}{2} \cdot 2} = 0^{2}$

Step 4.2.2.1.1.2

Cancel the common factor of $2$ .

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Step 4.2.2.1.1.2.1

Cancel the common factor.

${(4 x + 4)}^{\frac{1}{2} \cdot 2} = 0^{2}$

Step 4.2.2.1.1.2.2

Rewrite the expression.

${(4 x + 4)}^{1} = 0^{2}$

Step 4.2.2.1.2

Simplify.

$4 x + 4 = 0^{2}$

Step 4.2.3

Simplify the right side.

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Step 4.2.3.1

Raising $0$ to any positive power yields $0$ .

$4 x + 4 = 0$

Step 4.3

Solve for $x$ .

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Step 4.3.1

Subtract $4$ from both sides of the equation.

$4 x = - 4$

Step 4.3.2

Divide each term in $4 x = - 4$ by $4$ and simplify.

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Step 4.3.2.1

Divide each term in $4 x = - 4$ by $4$ .

$\frac{4 x}{4} = \frac{- 4}{4}$

Step 4.3.2.2

Simplify the left side.

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Step 4.3.2.2.1

Cancel the common factor of $4$ .

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Step 4.3.2.2.1.1

Cancel the common factor.

$\frac{4 x}{4} = \frac{- 4}{4}$

Step 4.3.2.2.1.2

Divide $x$ by $1$ .

$x = \frac{- 4}{4}$

Step 4.3.2.3

Simplify the right side.

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Step 4.3.2.3.1

Divide $- 4$ by $4$ .

$x = - 1$

Step 5

The domain is all values of $x$ that make the expression defined.

Interval Notation:

$(- 1, \infty)$

Set-Builder Notation:

${x | x > - 1}$

Step 6