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RE:[apcalculus] Need help plaease on 2008 BC MC # 17
Posted:
Sep 20, 2012 9:11 PM


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.  The short answer is that h(x^23) is a compostion of functions. That is, it is h(g(x)) where g(x)=x^23.
If you wanted to indicate the product of h and x^23 then you would write it as h(x)*(x^23).
HTH
Doug  Doug Kühlmann Math Dept Phillips Academy Andover, MA 01810
________________________________________ From: Qayumi, Enayat [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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