To find the new expression of \( a(x) = 8x \) after applying the transformations of being vertically stretched by a factor of 4 and reflected across the y-axis, we can follow these steps:
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Vertical Stretch: A vertical stretch by a factor of 4 means we multiply the entire function by 4. Thus, the function becomes: \[ a(x) = 4 \cdot (8x) = 32x \]
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Reflection Across the Y-axis: Reflecting the function across the y-axis means we replace \( x \) with \( -x \). So, we replace \( x \) in \( 32x \): \[ a(x) = 32(-x) = -32x \]
Combining these transformations together, the new expression is: \[ a(x) = -32x \]
However, the provided choices don't seem to match this exact transformation. Let's evaluate the options given:
- Option 1: \( a(x) = -4 \cdot 8^{-x} \)
- Option 2: \( a(x) = 8^{-x} - 4 \)
- Option 3: \( a(x) = 8^{-4x} \)
- Option 4: \( a(x) = 4 \cdot 8^{-x} \)
The transformations we applied resulted in \( a(x) = -32x \), which means none of the provided options exactly match this transformation. If \( 32x \) or \( 4 \cdot 8^{-x} \) to further adjust, we'd still be left on the mismatched option side.
Could you check for further clarifications on the options?