College Algebra : Review and Other Topics

Study concepts, example questions & explanations for College Algebra

varsity tutors app store varsity tutors android store

Example Questions

Example Question #3 : Complex Numbers

Possible Answers:

The answer is not present.

Correct answer:

Explanation:

Combine like terms:

Distribute:

Combine like terms:

Example Question #4 : Complex Numbers

Rationalize the complex fraction: 

Possible Answers:

Correct answer:

Explanation:

To rationalize a complex fraction, multiply numerator and denominator by the conjugate of the denominator.

Example Question #5 : Complex Numbers

Multiply: 

Possible Answers:

Correct answer:

Explanation:

Use FOIL to multiply the two binomials.

Recall that FOIL stands for Firsts, Outers, Inners, and Lasts.

Remember that 

Example Question #121 : Review And Other Topics

Simplify the following:

Possible Answers:

Correct answer:

Explanation:

To solve, you must remember the basic rules for i exponents.

Given the prior, simply plug into the given expression and combine like terms.

Example Question #121 : Review And Other Topics

Given the following quadratic, which values of  will produce a set of complex valued solutions for 

 

 

Possible Answers:

2 and 3 

1 and 3

1, 4, and 5

None of these, all produce real-valued solutions for 

1, 3 and 5 

Correct answer:

1, 3 and 5 

Explanation:

In order to determine if a quadratic equation  will have real-valued or complex-valued solutions compute the discriminate: 

 

If the discriminate is negative, we will have complex-valued solutions. If the discriminate is positive, we will have real-valued solutions. 

This arises from the fact that the quadratic equation has the square-root term, 

 

 

Evaluate the discriminate for 

  

 -79<0 so the quadratic has complex roots for 

 

Evaluate the discriminate for 

The discriminate is positive, therefor the quadratic has real roots for 

 

 

 

 

 

Example Question #13 : Complex Numbers

Evaluate:  

Possible Answers:

Correct answer:

Explanation:

Recall that , and .

Each imaginary term can then be factored by using .

Replace the numerical values for each term.

The answer is:  

Example Question #11 : Complex Numbers

Simplify:

Possible Answers:

Correct answer:

Explanation:

When simplifying expressions with complex numbers, use the same techniques and procedures as normal. 

Distribute the negative:

Combine like terms- combine the real numbers together and the imaginary numbers together:

This gives a final answer of 2+4i

Example Question #121 : Review And Other Topics

Simplify:

Possible Answers:

Correct answer:

Explanation:

When simplifying expressions with complex numbers, use the same techniques and procedures as normal. 

Distribute the sign to the terms in parentheses:

Combine like terms- combine the real numbers together and the imaginary numbers together:

This gives a final answer of 10-4i

Example Question #121 : Review And Other Topics

Simplify:

Possible Answers:

Correct answer:

Explanation:

When simplifying expressions with complex numbers, use the same techniques and procedures as normal. 

Distribute the sign to the terms in parentheses:

Combine like terms- combine the real numbers together and the imaginary numbers together:

This gives a final answer of 10+2i

Example Question #121 : Review And Other Topics

Simplify:

Possible Answers:

Correct answer:

Explanation:

When simplifying expressions with complex numbers, use the same techniques and procedures as normal. 

Distribute the sign to the terms in parentheses:

Combine like terms- combine the real numbers together and the imaginary numbers together:

This gives a final answer of 7+18i

Learning Tools by Varsity Tutors