Algebra II : Imaginary Numbers

Study concepts, example questions & explanations for Algebra II

varsity tutors app store varsity tutors android store

Example Questions

Example Question #4752 : Algebra Ii

Evaluate:  

Possible Answers:

Correct answer:

Explanation:

Write the first few powers of the imaginary term.

Change the higher ordered power by using the power rule of exponents.

A negative one to an odd power will be negative one.

The answer is:  

Example Question #72 : Basic Operations With Complex Numbers

Add  to its complex conjugate. What is the result?

Possible Answers:

Correct answer:

Explanation:

The complex conjugate of a complex number  is 

Therefore, the complex conjugate of  is . Add the two:

Collect real parts and imaginary parts:

The imaginary parts cancel out:

Example Question #2091 : Mathematical Relationships And Basic Graphs

Select the complex conjugate of  .

Possible Answers:

Correct answer:

Explanation:

The complex conjugate of a complex number  is , so the complex conjugate of  is .

Example Question #2092 : Mathematical Relationships And Basic Graphs

Evaluate .

Possible Answers:

Correct answer:

Explanation:

To raise  to the power of a negative integer, first raise  to the absolute value of that integer. Therefore, to find , we need to look at 

To raise  to the power of any positive integer, divide the integer by 4 and note the remainder. The correct power is given according to the table below.

Powers of i

, so  can be determined by selecting the power of  corresponding to remainder 2. This is 

Since , and by definition, , it follows that 

.

Example Question #4761 : Algebra Ii

Select the complex conjugate of 

Possible Answers:

 has no complex conjugate.

Correct answer:

Explanation:

 can be restated in standard complex number form as

.

The complex conjugate of a complex number  is , so the complex conjugate of  is , which is equal to . Therefore,  is the complex conjugate of .

Example Question #82 : Basic Operations With Complex Numbers

Select the complex conjugate of .

Possible Answers:

9 has no complex conjugate.

Correct answer:

Explanation:

 can be restated in standard complex number form as

.

The complex conjugate of a complex number  is , so the complex conjugate of  is , which is also equal to . Therefore,  itself is the complex conjugate of .

Example Question #83 : Basic Operations With Complex Numbers

Select the complex conjugate of .

Possible Answers:

Correct answer:

Explanation:

The complex conjugate of a complex number  is , so the complex conjugate of  is .

Example Question #84 : Basic Operations With Complex Numbers

Subtract  from its complex conjugate. What is the result?

Possible Answers:

Correct answer:

Explanation:

The complex conjugate of a complex number  is 

Therefore, the complex conjugate of  is . Subtract the former from the latter:

Collect real parts and imaginary parts:

The real parts cancel out:

Example Question #141 : Imaginary Numbers

Evaluate:

Possible Answers:

Correct answer:

Explanation:

In order to raise  to the power of a negative integer, first raise  to the absolute value of that integer. Therefore, to find , we need to look at 

To raise  to the power of any positive integer, divide the integer by 4 and note the remainder. The correct power is given according to the following table:

 Powers of i

, so  can be determined by selecting the power of  corresponding to remainder 3. This is 

Since , and by definition, , it follows that

Rationalize the denominator by multiplying by , the complex conjugate:

Example Question #85 : Basic Operations With Complex Numbers

Evaluate:

Possible Answers:

Correct answer:

Explanation:

To raise  to the power of any positive integer, divide the integer by 4 and note the remainder. The correct power is given according to the table below.

 Powers of i

, so  can be determined by selecting the power of  corresponding to remainder 0. The corresponding power is 1, so .

Learning Tools by Varsity Tutors