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问题: 求f(x)和g(x)

f(x)是偶函数 g(x)是奇函数
f(x)+g(x)=1/(x-1)

解答:

f(x)是偶函数,g(x)是奇函数,f(x)+g(x)=1/(x-1),求f(x)和g(x)

f(x)是偶函数,g(x)是奇函数--->f(-x)=f(x),g(-x)=-g(x)
f(x)+g(x)=1/(x-1).........................(1)
用-x代替x--->f(-x)+g(-x)=1/(-x-1)
--->f(x)-g(x)=-1/(x+1)....................(2)

[(1)+(2)]/2--->f(x)=[1/(x-1)-1/(x+1)]/2=1/(x²-1)
[(1)-(2)]/2--->g(x)=[1/(x-1)+1/(x+1)]/2=x/(x²-1)