Change a log
Compound Interest
Continuous Interest
Exponents
Solve it!
(log solutions as log or ln only)
Properties of Logarithms!
100

log_(1/2)(256)=-8

(1/2)^(-8)=256

100

You receive $5000 to invest in a bank account paying 4.5% interest compounded annually. If you leave the money in there for 15 years, how much will you have?

$9676.41

100

How much will you have at the end of 5 years if you leave $610 in an account with 8.4% interest compounded continuously?

$928.40

100

What is the domain of 

y=10e^x

The domain is all real numbers!

100

Solve 2x = 3

x=log(3)/log(2)

or

x=ln(3)/ln(2)

100

Condense the following logarithm:

log(4)+log(x)-log(z)

log((4x)/z)

200

log(5)=b

10^b=5

200

You receive $200 to invest in a bank account paying 12.1% interest compounded monthly. If you leave the money in there for 5 years, how much will you have?

$365.14

200

How much should you invest at 4.8% compounded continuously to have $5000 in 2 years.

$4542.32

200

Define an exponential equation p(t) for the following:

A colony of bacteria begins with 52 organisms and the population quintuples each day!  

How many bacteria are present after 3.4 days?

p(t)=52(5)^t

12373.7506 bacterial organisms based on our model

200

Solve 2x-1 = 17

x=(ln(17)+ln(2))/ln(2)

or

x=(log(17)+log(2))/log(2)

200

Expand the following logarithm:

log_9((2x^2)/y^8)

log_9(2)+2log_9(x)-8log_9(y)

300

log_w(m)=a

w^a=m

300

What amount must you invest in a bank account paying 11.1% interest compounded annually if you wish to have $10000 after 8 years?

$4308.12

300

How much should you invest at 9% compounded continuously to have $10000 in 8 years.

$4867.52

300

Change forms!

x^2-2x-3=(2x-2)^(e^(x-1))

log_(2x-2)(x^2-2x-3)=e^(x-1)

300

Solve 

log(x^2+1)-log(2)=log(13)

x=5,-5

300

Condense the following logarithm:

2ln(y)+ln(x^3)/2-ln(z)

ln((y^2x^(3/2))/z^2)

400

log_(x-1)(15)=(x+1)

(x-1)^(x+1)=15

400

If you invest $50 in a bank account paying 12% interest compounded quarterly, how long does it take if you wish to have $200?

t = 11.72 years

400

How long should you invest $10001 at 4.8% compounded continuously to have $5000?

(No Typo!!!!)

t = -14.4426 years or (go backward in time 14 years 161 days 13 hours 36 minutes and 34.343 seconds!)

400

What is the range of 

y=-2(1/3)^(x-1)-3

(-infty,-3)

400

Solve 

log_2(x-1)+log_2(x)=1

x=2

400

Expand the following logarithm:

log_166((11*10^3)/(7z^5))

log_166(11)+3log_166(10)-log_166(7)-5log_166(z)

or

log_166(11)+3log_166(10)-(log_166(7)+5log_166(z))

500

ln(x^2-15x+56)=-17

e^(-17)=x^2-15x+56

500

If you invest $322 in a bank account paying 2.2% interest compounded daily, how long does it take if you wish to have $400?

t= 9.86 years

500

What is the rate of the account giving you $13000 at the end of 6 years when you initially invested 

$e^8

r=.2455 or r=24.55%

500

For the exponential equation that goes through points (9, 140) and (10, 250) find the a and b values exactly and their approximations!

y=a(b)^x

a=250/(25/14)^10 approx .7583

or

b=25/14 approx 1.7857

500

Solve 

2^x=5^(x-1)

x=ln(5)/(ln(5)-ln(2))

x=log(5)/(log(5)-log(2))

500

Condense the following logarithm:

log_2(x)+log_5(y)-2log_2(z)+log_5(k)

log_2(x/(z^2))+log_5(yk)

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