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问题: 题1

求反函数
y=(2^x +1)/(2^x -1)

解答:

y=(2^x +1)/(2^x -1)(x≠0) →
y=[(2^x -1)+2]/(2^x -1) →
y=1 +[2/(2^x -1) ]→
2/(2^x -1)=y-1→
(2^x -1)/2=1/(y-1)→
2^x -1=2/(y-1)→
2^x =1+[2/(y-1)]→
2^x =(y+1)/(y-1)→
x=Log(2)[(y+1)/(y-1)]→(2)表以2为底
∴反函数 y=Log(2)[(x+1)/(x-1)](x<-1或x>1)



**(2)表以2为底