Download Practice Exam for Exam 3

Math 101
Practice Exam 3B
1. Write the following in the form a + bi:
a) (5 + 2i) 2 + (3 − 4i) 2
b)
3i
2 − 3i
2. Solve the inequalities for x, expressing the solution in interval notation:
a)
b)
2x
3
>
5x
12
−
1 − 2x ≤ 7
3
2
3. A stone is thrown upward from a height of 10 feet with an initial velocity of
80 ft./sec. The height of the stone t seconds after it has been thrown is given by the
function s(t) = −16t 2 + 80t + 10. Find the height of the stone after 10 seconds and the
maximum height the stone will reach.
4. Use algebra to solve for x:
a) x (x + 4) = 12
b) 3x 3 + x 2 – 3x = 0
c) x 2 + 12 = 0
5. Solve for x:
a)
5
1
+
=0
2x + 3 x − 6
b)
7x + 4 = x + 2
c)
2x − 3 + 4 = 8
d) x 3 + 5x 2 − 4x – 20 = 0
6. Lucy can be paid in one of two ways for refinishing a hardwood floor: with Plan A, she
receives $30 an hour; with Plan B, she receives $200 plus $15 an hour. If the job takes n
hours to complete, what values of n will make Plan B better than Plan A?
7. Let f(x) = (x 2 + 4) (6x – 3) 3 8x 2 . Find the zeros of f(x), the multiplicity of each zero of
f(x), and the degree of f(x).
8. Solve for B: A = (1 + 2B) 2
9. Provide the equation of a parabola which opens down and has vertex (−7, 18).