Question

带有字母的绝对值怎么算比如：f(x)=|x+1|-|x-1|f(-x)=|1-x|-|-x-1| =|x-1|-|x+1

Answer 1

如：|-1|=1,|1|=1,|-1|=|1|,那|x+1|=|-x-1|,|x-1|=|-x+1|=|1-x|, f（x）=|-x-1|-|1-x|,那f（-x）=|x-1|-|x+1|了