To determine the intervals over which the function is increasing, we can analyze the behavior of the branches as described in your question.
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First Branch: This branch starts just above the x-axis and approaches \( x = -1 \) from the left. As x increases from negative infinity towards -1, the function is increasing (since the y-values are increasing).
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Second Branch: This branch starts just below \( x = -1 \) and goes downwards until it reaches \( x = 1 \). Therefore, during this interval, the function is decreasing.
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Third Branch: This branch starts just to the right of \( x = 1 \) and increases as x goes towards positive infinity. Hence, the function is increasing in this interval.
Combining these observations, we find:
- The function is increasing on the interval \( \left( -\infty, -1 \right) \).
- It is also increasing on the interval \( \left( 1, \infty \right) \).
Thus, the overall intervals where the function is increasing are: \[ \left( -\infty, -1 \right) \cup \left( 1, \infty \right) \]
So the correct response is: left parenthesis negative infinity comma negative 1 right parenthesis union left parenthesis 1 comma infinity right parenthesis.