To convert the quadratic function given in vertex form \( f(x) = 3(x + 7)^2 - 2 \) to standard form, we need to expand the expression.
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Start by expanding the squared term: \[ (x + 7)^2 = x^2 + 14x + 49 \]
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Now substitute this back into the function: \[ f(x) = 3(x^2 + 14x + 49) - 2 \]
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Distribute the 3: \[ f(x) = 3x^2 + 42x + 147 - 2 \]
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Combine the constant terms: \[ f(x) = 3x^2 + 42x + 145 \]
So the standard form of the function is: \[ f(x) = 3x^2 + 42x + 145 \]
Among the choices presented, the equation that represents \( f \) in standard form is: \[ f(x) = 3x^2 + 42x + 145 \]