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RE: [apcalculus] Need help plaease on 2008 BC MC # 17
Posted:
Sep 21, 2012 7:47 AM


NOTE: This apcalculus EDG will be closing in the next few weeks. Please sign up for the new AP Calculus Teacher Community Forum at https://apcommunity.collegeboard.org/gettingstarted and post messages there.  Qayumi,
The notation h(x^2  3) like f(x) indicates a function, not a product, and therefore it is the Chain rule that is needed not the product rule.
Alan
Alan Lipp Williston Northampton School
Original Message From: Qayumi, Enayat [mailto:eqayumi@tusd.net] Sent: Thursday, September 20, 2012 1:18 PM To: AP Calculus Subject: [apcalculus] Need help plaease on 2008 BC MC # 17
NOTE: This apcalculus EDG will be closing in the next few weeks. Please sign up for the new AP Calculus Teacher Community Forum at https://apcommunity.collegeboard.org/gettingstarted and post messages there.   If h is a differentiable function and f(x) = h (x^2  3)
Why is the f'(x) = 2x h'(x^23) which will give the correct answer once you plug in x = 2
And Not
f'(x) = h' (x^2  3) + h (2x) due to the product rule? Once you find f'(2) = h' + 4h, it is not one of the MC options.
What am I missing? Thank you in advance for your response.
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