Q. Let h(x)=5−x−x3 and let f be the inverse function of h. Notice that h(−1)=7.f′(7)=
Find h′(x): Find h′(x), the derivative of h(x).h′(x)=−1−3x2
Evaluate h′(−1): Evaluate h′(−1) since h(−1)=7 and we need the derivative of the inverse function at h(−1).h′(−1)=−1−3(−1)2=−1−3(1)=−1−3=−4
Use inverse function property: Use the property of inverse functions that (f−1)′(b)=f′(a)1 where f(a)=b. Here, f−1 corresponds to h−1 and b=7, so we need to find h′(−1)1. (f−1)′(7)=h′(−1)1=−41=−41
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