题目

计算1-x分之1+1+x分之1+1+x的2方分之2+1+x的4方分之4=要过程阿
1+x分之x-1-x分之1-x的2方-1分之x的3方-2x+1求x=-2时的值

提问时间：2021-02-11

答案

1/(1-x)+1/(1+x)+2/(1+x^2)+4/(1+x^4)
=(1+x+1-x)/(1+x)(1-x)+2/(1+x^2)+4/(1+x^4)
=2/(1-x^2)+2/(1+x^2)+4/(1+x^4)
=2(1+x^2+1-x^2)/(1-x^2)(1+x^2)+4/(1+x^4)
=4/(1-x^4)+4/(1+x^4)
=4(1+x^4+1-x^4)/(1-x^4)(1+x^4)
=8/(1-x^8)
x/(1+x)-1/(1-x)-(x^3-2x+1)/(x^2-1)
=x/(1+x)+1/(x-1)-(x^3-2x+1)/(x^2-1)
=(x^2-x+1-x^3+2x-1)/(x^2-1)
=(-x^3+x^2+x-1)/(x^2-1)
=[-x^2(x-1)+(x-1)]/(x^2-1)
=(x-1)(1-x^2)/(x^2-1)
=-(x-1)
=1-x
=1-(-2)
=3