✔ 最佳答案
1.
f(x) = 7/2015 是一個常數函數。
不論 x 為任何數值,f(x) = 7/2015
(A) f(a + b + c) = 7/2015
(B) f(a) + f(b ‒ c) = (7/2015) × 2 = 14/2015
(C) f(a + b) + f(c) = (7/2015) × 2 = 14/2015
(D) f(‒a ‒b) + f(‒b ‒ c) + f(‒c ‒ a) = (7/2015) × 3 = 21/2015
...... 答案選(D)
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2.
f(0) = 5/0
因此,f(0) 無定義。
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3.
f(7.2)
= 50 + 20 × 8
= 210
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4.
f(1)
= f(‒1 + 2)
= k(‒1) ‒ 5
= ‒k ‒5
f(2)
= f(0 + 2)
= k(0) ‒ 5
= ‒5
3f(1) = 4f(2)
3(‒k ‒ 5) = 4(‒5)
‒3k ‒ 15 = ‒20
‒3k = ‒5
k = 5/3
2015-05-28 22:19:55 補充:
2.
若 f(x) = x/5
則 f(0) = 0/5
f(0) = 0