SAT2数学题目(level 2)
1.Solve for x in the following equation: x2 – 10x + 10 = 0.
(a) -5 +/- sqrt(15)
(b) 5 +/- sqrt(15)
(c) 5
(d) -5
(d) 5 +/- sqrt(5)
2.If log(x) = 2 and log(y) = 5, what is log(x2y3)?
(a) 11
(b) 15
(c) 17
(d) 19
(e) 29
3.What is the greatest common factor of 17 and 81?
(a) 1
(b) 17
(c) 3
(d) 9
(e) 27
4.In the (x,y) plane, which of the following statements are true?
I. Line y + x = 5 is perpendicular to line y - x = 5. II. Lines y + x = 5 and y - x = 5 intersect each other on the y axis. III. Lines y + x = 5 and y - x = 5 intersect each other on the x axis.
(a) I is the only true statement
(b) II is the only true statement
(c) I and II are both true
(d) I and III are both true
(e) II and III are both true
5.Find the domain of the function f(x) = √( -x) / [(x - 2)(x + 2)]:
(a) (-∞ , -2) U ( -2 , 0)
(b) (-∞ , -2) U ( -2 , 0]
(c) (-∞ , 2) U ( 2 , 0]
(d) (-∞ , 2) U ( 2 , 0)
(e) (-∞ , -2) U ( -2 , 2)
Explanation：
1. x = (10 +/- sqrt(100 - 40))/2 x = 5 +/- sqrt(15)
2.log(x2y3) = log(x2) + log(y3) = 2log(x) + 3log(y) = 4 + 15 = 19
3.17 = 17·1 81 = 3·3·3·3·1 The correct answer is (a).
4.y + x = 5 can be written as y = -x + 5. The slope of this equation is m1 = -1. y - x = 5 can be written as y = x + 5. The slope of this equation is m2 = 1. m2 = -1/m1 so the 2 lines are perpendicular. We also need to find where the 2 lines intersect. If we add the 2 equations, 2·y = 10, y = 5 From the first equation, x = 5 - y = 5 - 5 = 0. In conclusion the lines intersect at (0, 5) and this point is on the y axis. In conclusion I and II statements are correct.
5.From the numerator of the fraction, -x should be positive or equal to zero, so x<=0. x cannot take the values x = 2 and x = -2, so the domain of the function is (-∞ , -2) U ( -2 , 0]
以上就是这5道SAT2数学题目的全部内容，非常详细。SAT2数学考试练习题目一般并不是很多，所以需要大家在练习的时候，更多的把握其中的解题方法等内容。
