在每年的高考中，数学作为一门基础且重要的科目，备受考生和家长的关注。全国乙卷是高考数学试卷的一种，通常针对不同地区的考生特点进行设计。以下是对全国乙卷答案及解析的深度剖析，旨在帮助考生和家长更好地理解试卷内容和答案。
一、试卷结构分析
1. 题型分布
全国乙卷数学试卷通常包括以下几个部分：
- 选择题：包括单选题和多选题，考察基础知识和基本运算能力。
- 填空题：考察基础知识的灵活运用和简单问题的解决能力。
- 解答题：包括解答题和应用题，考察综合运用知识和解决问题的能力。
2. 试题难度
乙卷的难度一般介于甲卷和丙卷之间，旨在选拔中等水平以上的学生。
二、答案解析
1. 选择题解析
选择题通常考察学生对基础知识的掌握程度。例如：
例题： 若函数\(f(x) = x^2 - 4x + 3\)的图像关于直线\(x=2\)对称，则下列说法正确的是：
A. \(f(1) = f(3)\)
B. \(f(-1) = f(5)\)
C. \(f(0) = f(4)\)
D. \(f(2) = f(3)\)
解析： 由于函数图像关于直线\(x=2\)对称，可知\(f(2) = f(1)\)和\(f(2) = f(3)\)。故正确答案为D。
2. 填空题解析
填空题考察学生的计算能力和对基本概念的理解。例如：
例题： 已知等差数列\(\{a_n\}\)的第一项为\(a_1\)，公差为\(d\)，若\(a_1 + a_2 + a_3 = 6\)，\(a_4 + a_5 + a_6 = 18\)，则$a_1 = _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________