SAT数学练习题答案解析Question 4:
Answer: The coordinates of the 2 points are:
x1 = -1, y1 = 5, z1 = 3,
x2 = 2, y2 = 6, z2 = -1,
The distance in space between the points with coordinates (-1, 5, 3) and (2, 6, -1) squared is:
d2 = [(x1 - x2)2 + (y1 - y2)2 + (z1 - z2)2 ]= [ (-1 + (-2))2 + (5 - 6)2 + (3 - (-1)) 2 ] = 9 + 1 + 16 = 26
d = √26
SAT数学练习题答案解析Question 5:
Answer: We compare the equation of the circle, (x – 2)2 + (y + 2)2 = 16 with the general equation of a circle: (x – x1)2 + (y - y1)2 = R2,
where R is the radius of the circle.
We notice that the radius of our circle is √16 = 4
The area of the circle is ? · 42 = 16 · ?
SAT数学练习题答案解析Question 6:
Answer: |3 - 5| = |-2| = 2
|2 - 1| = |1| = 1
|-5| = 5
|3 - 5| - |2 - 1| + |-5| = 2 - 1 + 5 = 6
要想SAT2数学成绩有所提高，坚持每天做练习是十分必要的，就像这样每天完成SAT2数学Level 2练习题，并进行总结，日积月累，成绩就会有明显地提高。
