1. Suppose there are three functions, the first one is $y=\varphi(x)$, its inverse function is the second function, and the graph of the second function is symmetric to the graph of the second function about the line $x+y=0$, then the third function is
( A) $y=-\varphi(x)$
(B) $y=-\varphi(-x)$
(C) $y=-\varphi^{-1}(x)$
(D) $y=-\varphi^{-1}(-x)$
(B)
一、Multiple Choice Questions
1. 【Analysis and Solution】The graph of the first function is symmetric to the graph of the second function about $x-y=0$, and the graph of the second function is symmetric to the graph of the third function about $x+y=0$, so the graph of the first function is symmetric to the graph of the third function about the origin.