设f(x+x-1)=x3+x-3 g(x+x-1)=x2+x-2,求f(g(x))
答案:2 悬赏:30 手机版
解决时间 2021-01-29 11:12
- 提问者网友:嗝是迷路的屁
- 2021-01-28 21:13
设f(x+x-1)=x3+x-3 g(x+x-1)=x2+x-2,求f(g(x))
最佳答案
- 五星知识达人网友:撞了怀
- 2021-01-28 21:29
f(x+1/x)=x³+1/x³
g(x+1/x)=x²+1/x²
a=x+1/x
则a²=x²+2+1/x²
x²+1/x²=a²-2
所以g(a)=a²-2
x³+1/x³
=(x+1/x)(x²-1+1/x²)
=a(a²-1)
=a³-a
所以f(a)=a³-a
所以f[g(x)]
=(x²-2)³-(x²-2)
=x^6-6x^4+11x³-6
g(x+1/x)=x²+1/x²
a=x+1/x
则a²=x²+2+1/x²
x²+1/x²=a²-2
所以g(a)=a²-2
x³+1/x³
=(x+1/x)(x²-1+1/x²)
=a(a²-1)
=a³-a
所以f(a)=a³-a
所以f[g(x)]
=(x²-2)³-(x²-2)
=x^6-6x^4+11x³-6
全部回答
- 1楼网友:孤独的牧羊人
- 2021-01-28 21:57
你好!
1/x(4-x)
=-(1/4)*4/(x-4)x
=-(1/4)*[x-(x-4)]/(x-4)x
=-(1/4)*[x/(x-4)x-(x-4)/(x-4)x]
=-(1/4)*[1/(x-4)-1/x]
所以原式=(-1/4)∫[1/(x-4)-1/x]dx
=(-1/4)(ln|x-4|-ln|x|)+C
打字不易,采纳哦!
我要举报
如以上问答信息为低俗、色情、不良、暴力、侵权、涉及违法等信息,可以点下面链接进行举报!
大家都在看
推荐资讯