SAT SUBJECT TEST MATH LEVEL 2
PART 2
REVIEW OF MAJOR TOPICS
CHAPTER 1
Functions
1.2 Polynomial Functions
INEQUALITIES
Given any algebraic expression f(x), there are exactly three situations that can exist:
1. for some values of x, f(x) < 0;
2. for some values of x, f(x) = 0;
3. for some values of x, f(x) > 0.
If all three of these sets of numbers are indicated on a number line, the set of values that satisfy f(x) < 0 is always separated from the set of values that satisfy f(x) > 0 by the values of x that satisfy f(x) = 0.
EXAMPLE
Find the set of values for x that satisfies x2 – 3x – 4 < 0.
Graph y = x2 – 3x – 4. You need to find the x values of points on the graph that lie below the x-axis. First find the zeros: x = 4, x = –1. The points that lie below the x-axis are (strictly) between –1 and 4, or –1 < x < 4.
EXERCISES
1. Which of the following is equivalent to 3x2 – x < 2?
(A)
(B)
(C)
(D)
(E)
2. Solve x5 – 3x3 + 2x2 – 3 > 0.
(A)
(B) (–1.90,–0.87)
(C)
(D) (–0.87,1.58)
(E)
3. The number of integers that satisfy the inequality x2 + 48 < 16x is
(A) 0
(B) 4
(C) 7
(D) an infinite number
(E) none of the above