Question:medium

Consider the following expression.
\[ \lim_{x \to -3} \frac{\sqrt{2x + 22} - 4}{x + 3} \] The value of the above expression (rounded to 2 decimal places) is \(\underline{\hspace{2cm}}\).

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For limits involving square roots, rationalizing the numerator helps remove indeterminate forms.
Updated On: Jan 30, 2026
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Correct Answer: 0.25

Solution and Explanation

Step 1: Observe the indeterminate form.
Direct substitution of x = −3 gives the form 0 / 0, so we simplify the expression.


Step 2: Rationalize the numerator.

\[ \frac{\sqrt{2x+22} - 4}{x+3} \times \frac{\sqrt{2x+22} + 4}{\sqrt{2x+22} + 4} \]

\[ = \frac{(2x+22) - 16}{(x+3)(\sqrt{2x+22} + 4)} \]

\[ = \frac{2x + 6}{(x+3)(\sqrt{2x+22} + 4)} \]

\[ = \frac{2(x+3)}{(x+3)(\sqrt{2x+22} + 4)} \]


Step 3: Cancel the common factor.

\[ = \frac{2}{\sqrt{2x+22} + 4} \]


Step 4: Substitute x = −3.

\[ = \frac{2}{\sqrt{16} + 4} = \frac{2}{8} = 0.25 \]


Final Answer:

0.25

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