MATH 1210 - Section 002
Fall 2010
Quiz 2
Name:
September 9, 2010
Directions: Write legibly, the use of documents is forbidden, giving or receiving aid on this assignement
is forbidden. You will get zero if any of these happen.
√
1. Let f (x) = x, g(x) = x2 − 16 and h(x) = x + 9.
Find the domain of ( f g◦h )(x). 3 points
Answer ( f g◦h )(x) =
x3 −1
.
2
x→1 x −1
2. Find lim
so the domain of this function is [−9, −4) ∪ (−4, 4) ∪ (4, ∞)
3 points
x3 −1
2
x→1 x −1
Answer lim
sqrtx+9
(x−4)(x+4) ,
= lim
x→1
(x−1)(x2 +x+1)
(x−1)(x+1)
=
3
2
3. An open rectangular box with volume 2m3 has a square base. Express the surface area of the box as
a function of the length of a side of the base. Justify your answer. 4 points
Answer S(x) = x2 +
8
x