Pg. 255/268 Homework
• Pg. 277 #32 – 40 all
Pg. 292 #1 – 8, 13 – 19 odd
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#6
#24
#35
#1
#5
#9
left 2, up 4
#14
7
56
14
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x= 8
8
4
Graph
#51
Graph
#3
down 4
#7
left 1, up 7
#15
Graph
#28 x = 6
r = 6.35, h = 9, V = 380
a) dec b) inc c) dec
right 3
a=c
5.1 Exponential Functions
• Suppose the half-life of a certain radioactive
substance is 20 days and there are 5g present
initially. Draw a complete graph of an
algebraic representation of this problem
situation and find when there will be less than
1g of the substance remaining.
5.2 Simple and Compound Interest
Simple Interest
• Suppose P dollars are
invested at a simple interest
rate r, then the simple
interest formula for the
total amount T after n
interest periods is:
T = P(1 + nr)
Example:
• Silvia deposits $500 in an
account that pays 7% simple
annual interest. How much
will she have saved after 10
years?
5.2 Simple and Compound Interest
Compound Interest
• Compound Interest is when
financial institutions pay
interest on the interest.
• Suppose P dollars are
invested at an interest rate
r, then the compound
interest formula for the
total amount S after n
interest periods is:
S = P(1 + r/n)nt
Example
• Suppose $500 is invested at
7% interest compounded
annually. Find the value of
the investment after 10
years.
• How much should be
invested at 6.25%
compounded semi-annually
in order to have an
investment of $1,500 after 5
years?
5.2 Simple and Compound Interest
Compound Interest
• Suppose $1000 is invested
at 8%. Find the value of the
investment after one year
when it is compounded
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Annually
Quarterly
Monthly
Weekly
Daily
Hourly
Continuous Interest
• If P dollars are invested at
APR r (in decimal form) and
compounded continuously,
then the value of the
investment after t years is
given by:
S = Pert