Algebra II : Logarithms

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #61 : Logarithms

Simplify, if possible:  

Possible Answers:

Correct answer:

Explanation:

Notice that the term in the log can be rewritten as a base raised to a certain power.

Rewrite the number in terms of base five.

According to log rules, the exponent can be dropped as a coefficient in front of the log.

The answer is:  

Example Question #62 : Logarithms

Solve:  

Possible Answers:

Correct answer:

Explanation:

Evaluate the log using the following property:

The log based and the base of the term will simplify.

The expression becomes: 

The answer is:  

Example Question #61 : Logarithms

Try to answer without a calculator.

True or false:

Possible Answers:

True

False

Correct answer:

False

Explanation:

By definition,  if and only if . However, 

,

making this false.

Example Question #64 : Logarithms

Try without a calculator:

Evaluate 

Possible Answers:

None of the other choices gives the correct response.

Correct answer:

Explanation:

By definition,  if and only if .

8 and 16 are both powers of 2; specifically, . The latter equation can be rewritten as

By the Power of a Power Property, the equation becomes

or

It follows that

,

and

,

the correct response.

Example Question #65 : Logarithms

Solve for  (nearest tenth):

.

Possible Answers:

Correct answer:

Explanation:

By definition,  if and only if . Set , and

if and only if

Through calculation, we see that

.

Example Question #62 : Logarithms

Try to answer without a calculator:

Which is true about ?

Possible Answers:

 is an undefined quantity

Cannot be determined

Correct answer:

 is an undefined quantity

Explanation:

The question asks for the value of the "base 0 logarithm" of 0. However, this is not defined, as a logarithm can only have as its base a positive number not equal to 1. 

Example Question #67 : Logarithms

Given the following:

Decide if the following expression is true or false:

 for all positive .

Possible Answers:

False

True

Correct answer:

True

Explanation:

By definition of a logarithm,

 

if and only if 

Take the th root of both sides, or, equivalently, raise both sides to the power of , and apply the Power of a Power Property:

or

By definition, it follows that , so the statement is true.

 

Example Question #68 : Logarithms

, with  positive and not equal to 1.

Which of the following is true of  for all such  ?

Possible Answers:

Correct answer:

Explanation:

By definition,

If and only if

Square both sides, and apply the Power of a Power Property to the left expression:

It follows that for all positive  not equal to 1,

 

for all .

Example Question #1 : Logarithms

What is the value of  that satisfies the equation  ?

Possible Answers:

Correct answer:

Explanation:

 is equivalent to . In this case, you know the value of  (the argument of a logarithmic equation) and b (the answer to the logarithmic equation). You must find a solution for the base.

Example Question #1 : Multiplying And Dividing Logarithms

Rewrite the following logarithmic expression in expanded form (i.e. as a sum and/or difference):

Possible Answers:

Correct answer:

Explanation:

By logarithmic properties:

;

Combining these three terms gives the correct answer:

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