Question

高中数学题，求这两道题的解答过程

Answer 1

1. f(0) - g(0) = 1 > 0 ==> f(0) > g(0)
f(1) - g(1) = e f(-1) - g(-1) = 1/e
e > 1/e
f(1) - g(1) > f(-1) - g(-1)
g(1) = g(-1)
所以 f(1) > f(-1)
且 f(1) > f(0) > f(-1)
答案是 f(1) > g(0) > f(-1) 或 f(1) > f(-1) > g(0)
所以选C
2. 3a(4) + a(12) > 0
用公式 a(n) = a(1) + (n-1) d
4a(1) + 20d > 0
a(1) + 5d > 0
a(6) > 0
S(12) = 6a(1) + 6a(12) < 0
a(1) + a(12) < 0
2a(1) + 11d <0
a(1) + 5.5d <0
即a(6)往後都为负值 最大值为 S(6)

追问

幸苦了兄弟

Answer 2

。。。根本看不清