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Let f be the function defined by f(x)=x³−7x². If g(x)=5f(x) and f(1)=13, what is the value of g′(13)?

User Pfg
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Final answer:

To find g'(13), we must first compute f'(x), which is the derivative of f(x) = x³ - 7x². Then we solve for x in g(x) = 13. Finally, substitute that x-value into g'(x) = 5f'(x) to get g'(13).

Step-by-step explanation:

The given function is f(x) = x³ - 7x². The function g(x) = 5f(x), so to find g'(x), we first need to find f'(x). The derivative of f(x) with respect to x is f'(x) = 3x² - 14x. Substituting x = 1 into f'(x) doesn't give us g'(13), because we're looking for g'(x) evaluated at an x-value that makes g(x) equal to 13. However, the information about f(1) = 13 is a typo and irrelevant to solving for g'(13). Instead, we need to evaluate f'(x) at the x-value where g(x) = 13, which requires solving g(x) = 13 for x, then using that x-value in g'(x) = 5f'(x).

User EngineerDanny
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