This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: MAC1147: Quiz #2
09/08/2009
In the topright corner of a clean sheet of paper, write your name, UFID,
and section number. Please use a pen with blue or black ink. When you are
nished, FOLD your paper in half lengthwise and write your name on the
back.
1. Simplify 2x2 − 9x + 4
and nd its domain.
12 + x − x2
2x2 − 9x + 4
(2x − 1)(x − 4)
(2x − 1)
=−
=−
12 + x − x2
(x + 3)(x − 4)
(x + 3) Here the domain is simply x = −3; x = 4. In interval notation:
(−∞, −3) ∪ (−3, 4) ∪ (4, ∞).
2. Solve: x4 − 5x2 + 6 = 0. (Hint: Use a substitution)
Let u = x2 . Then the equation becomes u2 − 5u + 6 = 0, which can be
solved as follows:
(u − 3)(u − 2) = 0
u = 3; u = 2
x2 = 3; x2 = 2
√
√
x = ± 3; x = ± 2 3. Solve the inequality: −3 2 + x
≤ −6
3
x Dividing both sides by −3 gives 2 +  ≥ 2 (don't forget that the
3
inequality ips when we multiply or divide by a negative!). From here
1 x x the problem splits into two separate inequalities: 2+ ≥ 2 and 2+ ≤
3
3
−2, which are easily solved to obtain x ≥ 0 and x ≤ −12, respectively. 2 ...
View
Full
Document
 Summer '08
 GERMAN
 Calculus

Click to edit the document details