Logarithms

WHAT?

1

Use the Change of base formula to evaluate: log₅34

(Round to 4 decimal places)

2.1911

2

Evaluate log -15

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3

Evaluate log 100 without a calculator

2

4

Rewrite  y = 8^x  in log form

log₈ y = x

5

The original value of an investment is $1400, and the value increases by 9% each year. Use an exponential growth function to find the value of the investment after 25 years. 

Formula: y=a(1+r)^t

$12072.31

ARE U KIDDING?

1

Logarithms with an invisible base have a base of _?_ and are called _?_ logs.

10, common

2

Evaluate log₂₅ 5 without a calculator

1/2

3

The inverse of an exponential function is a __?__

logarithmic function

4

Write the following in log form:

3^-4=1/81

log₃1/81=-4

5

Evaluate log₇ 343 without a calculator

3

FOR REAL?

1

Classify as an exponential growth or decay: 

f(x)=3(6/5)^x-4

Growth

2

Evaluate log .63 to the nearest thousandth

-.201

3

A line that a graph approaches but does not touch is called an __?__. (Extra point for spelling)

asymptote

4

The base of a logarithm cannot be _?_, _?_, or

_?_.

0, 1, or negative

5

Evaluate log₄ 1/64 without a calculator

-3

COME ON NOW?

1

Evaluate log .014 to the nearest thousandth.

-1.854

2

How many weeks are in a year

52

3

Rewrite log₆ 216 = 3 in exponential form 

6³ = 216

4

Evaluate log 24 to the nearest hundredth

1.38

5

Suppose a savings account offers 0.7% interest rate compounded monthly. If you open an account with $1200 and make no other withdrawals, how much INTEREST will you have earned after 15 years? 

Total: $1332.82

Interest $132.82

HUH?

1

Rewrite log₉ 3 = 1/2 in exponential form

9^1/2 = 3

2

Evaluate log 1 without a calculator

0

3

Find x

log_x81=2

9

4

Find x

log_1/21/32=x

5

5

Evaluate log_1/6 36 without a calculator

-2