高数题求高手!设f(x)=ln{x-(x^2-x^2)^(1/2)},其中x>y>0,则f(x+y,x-y)等于?A.2ln(x^（1/2）-y^(1/2))B.ln(x-y)C.(1/2)(lnx-lny)D.2ln(x-y)

Question

高数题求高手!
设f(x)=ln{x-(x^2-x^2)^(1/2)},其中x>y>0,则f(x+y,x-y)等于?
A.2ln(x^（1/2）-y^(1/2)) B.ln(x-y) C.(1/2)(lnx-lny) D.2ln(x-y)

Answer 1

选A,首先你先检查一下你的题目,你写错了.后面一个X应该是Y.解法是把x+y和x-y分别代入化简