12月SAT考前练习之每日数学

　　在新SAT的考试中，数学最应该得到重视，因为在满分1600分中，数学单项占50%的计分份额。美国的数学要求和题目的运算难度非常基础，几乎达不到中国的中学数学教育的“低端线”。但期望得到高分的学生往往在数学部分出现疏漏。其实是大多数学生SAT数学丢分的主要原因：单词不认识。很简单，如果题目需要你选中一个integer，而你并不知道integer的意思是“整数”，那么这道题目你就不能确保答对。下面课窝网为大家送上两个例子，检测一下自己吧。

　　例1：

　　During the process of radioactive decay, a "parent" material produces a new "daughter" material, which further decays into a stable material. During an experiment involving radioactive decay, the mass M, in micrograms, of daughter material changes over time t, measured in hours as shown in the graph above. What is the significance of the point shown on the graph?

　　A.The point shows the mass of the daughter material at the beginning of the experiment.

　　B.The point shows the mass of the daughter material when the mass was increasing at its fastest rate.

　　C.The point shows the amount of time the daughter material takes to decay into stable material.

　　D.The point shows the maximum mass of the daughter material and the number of hours since it was created that its mass reached this maximum.

　　答案：D

　　解析：

　　Choice D is correct. The point indicated is the highest point on the graph. Since t represents the time in hours since the daughter material was created and M represents the mass of the daughter material, the point shows the values of t and M when M is greatest. Therefore, the point shows the maximum mass of the produced substance and the number of hours since it was created that its mass reached this maximum.

　　例2：

　　Tonya hits a golf ball from an initial height of 10 feet. The height of the golf ball, h, in feet above sea level, t seconds after the ball was hit, can be modeled by a quadratic equation. If the golf ball reaches its maximum height of 74 feet exactly 2 seconds after it has been hit, which of the following equations represents this relationship?

　　A.h=10(t-2)^2+74

　　B.h=-10(t+2)^2+74

　　C.h=-16(t-2)^2+74

　　D.h=16(t+2)^2+74

　　答案：C

　　以上就是小编为大家介绍的关于SAT数学备考近练习题。更多SAT考试科目、SAT考试地点等问题可以咨询我们。