College Algebra
INSTRUCTIONS: You should read (as many times as necessary) Sections 5.1-5.2 in our
text. You should know how to complete the following problems:
Section 5.1 #1-45 (Odds)
Section 5.2 #1-45 (Odds)
The following problems should be turned in NO LATER than the beginning of class on
Nov 24. To receive FULL credit you must answer the following questions on a
separate sheet of paper. Your answers must also be legible and show complete
detail. If you are unsure what this means please contact me.
1. Let
f(x) = 2x ?? 5:
(a) Prove that f(x) is one-to-one using the denition we stated in class.
(b) Determine a formula for the inverse f??1(x):
2. Let
g(x) = (x ?? 5)3 + 4:
(a) Prove that g(x) is one-to-one using the denition we stated in class.
(b) Determine a formula for the inverse g??1(x):
3. Consider the beautiful function
A(t) = P
1 +
r
n
nt
:
This function is used to determine how an investment of P dollars grows after t years
if the interest (at rate r) is compounded n times per year.
Suppose that $25; 000 is invested at 3:7% interest, compounded quarterly. Determine
the amount of money in the account at t = 0; 5; and 30 years.
1