题目

 “What’s in a name?” According to Shakespeare’s Romeo and Juliet, there is not too much. “That which we call a rose by any other name would smell as sweet.” But Shakespeare may have been wrong. In most cultures, names matter a great deal. Americans choose names for their children with care. Parents usually think about the impression a name gives, not its meaning. Most Americans would consider a “Jennifer” more attractive than a “Bertha”, for example. The last name, or, surname, must also be considered when choosing a first and middle name. A name like Lester Chester已知x2+（a+3）x+a+1=0是关于x的一元二次方程．（1）求证：方程总有两个不相等的实数根；（2）若方程的两个实数根为x1 ， x2 ， 且x12+x22=10，求实数a的值．