複選題
6.已知二次函數 y = (3-k)x2-kx的圖形恆在y =k的上方,則k直有可能爲下列何者?
(A) 6
(B)2
(C) -2
(D) -6
(E) -10

答案:登入後查看
統計: A(7), B(12), C(19), D(16), E(14) #871774

詳解 (共 1 筆)

#1471440

答案為(C)

 y = (3-k)x2-kx=(3-k)(x-k/(2(3-k)))2-k*k/(4(3-k))
-k*k/(4(3-k))>k
0>k+k*k/(4(3-k))=3k(4-k)/(3-k)
1.k<3
k>4或k<0
2.k>3
o<k<4

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