Let's break this down step by step.
Part 1: Graph of the Function
The function \( f(x) \) is defined as:
- \( f(x) = 4x - 4 \) if \( x \leq 2 \)
- \( f(x) = x^2 \) if \( x > 2 \)
To analyze it:
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For \( x \leq 2 \):
- \( f(2) = 4(2) - 4 = 8 - 4 = 4 \)
- The linear function \( f(x) = 4x - 4 \) extends from point \( (2, 4) \) to the left, and it is a downward-sloping ray.
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For \( x > 2 \):
- The function is quadratic (specifically \( f(x) = x^2 \)), which starts at an open point \( (2, 4) \) and opens upwards.
Now, we can look for the graph that correctly represents this description:
- The graph must have a downward ray starting at \( (2, 4) \) and covering values less than or equal to \( 2 \).
- The quadratic part must start from \( (2, 4) \) and curve upwards from there.
Option D is the correct answer, as it shows:
- A ray starting from \( (2, 4) \) and falling to the left.
- An upward-opening curve starting from \( (2, 4) \).
Part 2: Evaluate \( f(1) \) and \( f(4) \)
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Finding \( f(1) \):
- Since \( 1 \leq 2 \), use \( f(x) = 4x - 4 \): \[ f(1) = 4(1) - 4 = 4 - 4 = 0 \]
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Finding \( f(4) \):
- Since \( 4 > 2 \), use \( f(x) = x^2 \): \[ f(4) = 4^2 = 16 \]
So:
- \( f(1) = 0 \)
- \( f(4) = 16 \)
Part 3: Domain of the Function
The function combines two pieces:
- For \( x \leq 2 \), \( f(x) \) is defined.
- For \( x > 2 \), \( f(x) \) is also defined.
Thus, the domain of the function is all real numbers since both pieces cover all possible values of \( x \).
The correct option is: D. The domain of the function is all real numbers.
Summary of Answers
- Part 1: The correct graph is D.
- Part 2: \( f(1) = 0 \) and \( f(4) = 16 \).
- Part 3: The domain of the function is D. all real numbers.