Recursion
Logarithms
Geometric Sequences
Compound Interest/Continuously
100

The swallowtail butterfly population grows at a rate of 7% monthly due to EPA efforts to reduce air pollution. If there were initially 3,000 butterflies in this environment, how many swallowtails will live in this area after 3 years (36 months)? -->

34,272 butterflies, WOW

100

Solve for x: log71 = x

x = 0

100

4 + 8 + 16 + ......... + 256

508

100

 You've deposited $10,000 into a bank account with 1.8% interest rate compounded quarterly. What is the Effective Annual Interest Rate of this account? 

***EAY = (1 + r/n)(n)(1) in the compound interest formula or (er1 ) in the compound continuously formula

1.01812 = 1.812% EAY

200

The number of fish in a nearby artificial lake decreases by 20% each year.  To maintain the fish population,
the lake is restocked with fish at a rate of 30,000 fish per year. Suppose there are 280,000 fish in the lake
initially. Write a recursive system to model the number of fish in the lake, 𝐹(n), after n years.

 F(n) = Fn-1(.8) + 30,000

200

Solve for HA: f(x) = log4(x - 9)

x = 9

200

3 + 1.5 + .75 + .375 + ...... + .00585

Approx. 5.994

200

Carbon-14 has been used to date the La Brea tar pits by testing remains of Saber tooth tigers. Carbon-14 has a half-life of 5,730 years. The initial mass of carbon-14 abundant in a saber tooth femur is 1 microgram. 

a) Find a function that models the amount of the sample remaining t years after the Saber Tooth Tiger died. 

*hint: use the formula of half life: A = p(1/2)(t/HL)

A = 1(1/2) ^ (t/5730)

300

The number of fish in a nearby artificial lake decreases by 20% each year.  To maintain the fish population, the lake is restocked with fish at a rate of 30,000 fish per year. Suppose there are 280,000 fish in the lake initially. What will happen to the fish population in the long run? 

150,000

300

Solve for x: log52 + log5x = 3

x = 62.5

300

Find the geometric sum if a=9/10, r=1/10, and k=99

.999; approx 1


300

Recently, you've received an unexpected $10,000 inheritance. You plan deposit this into a bank account with a 1.8% annual interest compounded daily. How much money will be in the bank account after 5 years?

(Hint hint, compound interest formula)

$10,941.72

400

The number of fish in a nearby artificial lake decreases by 20% each year.  To maintain the fish population, the lake is restocked with fish at a rate of 30,000 fish per year. Suppose there are 280,000 fish in the lake initially. How many fish would need to be added to the lake each year for the population to stabilize at 225,000?

45,000 must be added per year!


400

Solve for x: log5252 = x

x = 4

400

5/2 + 5/22 + 5/23 + ..... + 5/210

4.99

400

You've deposited $1000 into a bank account with a 4% interest rate is compounded continuously. How much money do you have after 10 years?

$1491.82

500

Mrs. Belledin is having a pest problem in her garden. She wants to add 3,000 ladybugs per week to naturally solve the problem. The initial ladybug population in her garden is 50,000. The ladybug population decreases by 9% each week. How many ladybugs will she have after 4 weeks?

She will have 44,762 ladybugs! :D


500

Solve for x: log3(2x+6) = log3(42)

*Hint: one to one property

x = 18

500

6 - 18 + 54 - 162 + 486 -1458

1095

500

In your own words, describe what e represents.

max return on investment when you compound continuously