1. Let f(x) = x^3+(k-1)x^2+3x+2, where k is a constant. If the equation f '(x)=0 has only one real solution, find the possible values of k.
2. If f(x) = (a+x)(a-x)^1/2, where a is a positive constant, find the value of f '(0).
M1 differnetiation
2010-11-15 1:00 am
回答 (1)
2010-11-15 1:13 am
✔ 最佳答案
1 f'(x)=3x^2+2(k-1)x+3 which has only one rootdiscriminant=4(k-1)^2-36=0
k-1=3 or k-1=-3
k=4 or k=-2
2 f(x) = (a+x)√(a-x)
f'(x)=(-1/2)(a+x)/√(a-x)+√(a-x)
f'(0)=(-1/2)(a)/√(a)+√(a)=√a/2
收錄日期: 2021-04-13 17:39:19
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https://hk.answers.yahoo.com/question/index?qid=20101114000051KK01113