题目

Celebrities （名人）  have become a powerful influence on some people because of their social position and their economic situation．First, some people admire and imitate stars because they allow themselves to be influenced by the media． Television, radio, and magazines invade the lives of spectators （观众） with a variety of shows, information, and publications about stars and their lives．  For instance, Britney Spears has become the target of paparazzi （狗仔队）．  In May, Britney appeared at the front page of the most popular magazines revealing that she married her 9．牛顿法求方程f（x）=0近似根原理如下：求函数y=f（x）在点（xn，f（xn））处的切线y=f′（xn）（x-xn）+f（xn），其与x轴交点横坐标xn+1=xn-$\frac{f（{x}_{n}）}{f′（{x}_{n}）}$（n∈N*），则xn+1比xn更靠近f（x）=0的根，现已知f（x）=x2-3，求f（x）=0的一个根的程序框图如图所示，则输出的结果为（　　）A．2B．1.75C．1.732D．1.73