Algebra II : Number Theory

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #21 : Real Numbers

Which of the following are NOT real numbers?

Possible Answers:

Correct answer:

Explanation:

Real numbers may include positive and negative integers, rational numbers, and also irrational numbers.  

Rational numbers are terms that can be expressed as ratios of numbers, such as .

Real numbers cannot include infinity or imaginary numbers, such as .

However, the imaginary term provided in the answer choice is not fully simplified.

This value is a real number.

The term  is an irrational number, and is considered a real number.  

The term  is also irrational, and is a real number.

The correct answer is:  

Example Question #1 : Types Of Numbers

Which of the following describes the number ?

Possible Answers:

real, natural

imaginary, irrational

real, irrational

real, rational

Correct answer:

real, irrational

Explanation:

is a real number, because you can represent it on the Cartesian coordinate plane, but it is irrational because it cannot be represented by a fraction of two integers. Natural numbers are integers greater than 0.

Example Question #2 : Types Of Numbers

Which of the following sets of numbers contain only natural numbers.

Possible Answers:

Correct answer:

Explanation:

Natural numbers are simply whole, non-negative numbers. 

Using this definition, we see only one set of numbers within our answer choices containing only whole, non-negative numbers. Any set containing decimals or negative numbers, will violate our defintion of natural numbers and thus be an incorrect answer. 

Example Question #3 : Types Of Numbers

What is the value of  ?

Possible Answers:

Correct answer:

Explanation:

There is a repeating pattern of four exponent values of .

 is the same as .

Example Question #4 : Types Of Numbers

Simplify .

 

Possible Answers:

Correct answer:

Explanation:

Multiplying out using FOIL (First, Inner, Outer, Last) results in,

 .

Remember that   

Example Question #5 : Types Of Numbers

Which of these numbers is prime?

Possible Answers:

Correct answer:

Explanation:

For a number to be prime it must only have factors of one and itself.

10 has factors 1, 2, 5, 10.

15 has factors 1, 3, 5, 15.

18 has factors 1, 2, 3, 6, 9, 18.

The only factors of 13 are 1 and 13. As such it is prime.

Example Question #6 : Types Of Numbers

Which of the below is an irrational number?

Possible Answers:

Correct answer:

Explanation:

Irrational numbers are defined by the fact that they cannot be written as a fraction which means that the decimals continue forever. 

Looking at our possible answer choices we see,

 is already in fraction form

 which is an imaginary number but still rational.

Therefore since,

 

we can conclude it is irrational.

Example Question #7 : Types Of Numbers

Which of the following describes the type of ?

Possible Answers:

None of these options describe .

 is imaginary, rational

 is real, rational

 is real, irrational

 is imaginary, irrational

Correct answer:

 is real, irrational

Explanation:

An irrational number is a number that cannot be written in fraction form. In other words a nonrepeating decimal is an irrational number.

The  is an irrational number. 

 is a real number with a value of .

Therefore, . This is a real but irrational number.

Example Question #3 : Types Of Numbers

What is the most specific classification for the x-intercepts to the equation graphed:

Exam transform 2

Possible Answers:

real

imaginary

integer

rational

irrational

Correct answer:

imaginary

Explanation:

The graph shown never intersects with the x-axis. This means that the x-intercepts must be imaginary.

Example Question #4 : Types Of Numbers

What is the most specific classification for

Possible Answers:

irrational

natural number

rational

counting number

imaginary

Correct answer:

irrational

Explanation:

The square root of 5 is irrational since it is a non-terminating, non-repeating decimal that cannot be expressed as a fraction.

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