Algebra 2 - How to divide complex numbers (-5-9i) / (9+8i)

Algebra 2 - How to divide complex numbers (-5-9i) / (9+8i)

Assessment

Interactive Video

Mathematics

11th Grade - University

Hard

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The video tutorial explains how to divide complex numbers using conjugates. It begins by discussing the initial approach of multiplying by i over i and highlights the limitations when dealing with binomials. The teacher introduces the concept of conjugates and demonstrates how to multiply binomials in both the numerator and denominator. The tutorial concludes with simplifying the expression by combining like terms and using the property of i squared.

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7 questions

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1.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the initial step when dividing complex numbers with a binomial denominator?

Add the real parts

Multiply by i over i

Subtract the imaginary parts

Use the conjugate of the denominator

2.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

Why can't we simply multiply by 'i' when the denominator is a binomial?

It eliminates the real part

It makes the expression more complex

It only works for monomials

It doesn't change the denominator

3.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the conjugate of a complex number?

The negative of the number

The reciprocal of the number

The same number with the opposite sign of the real part

The same number with the opposite sign of the imaginary part

4.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the result of multiplying two conjugates?

A complex number

An imaginary number

A real number

Zero

5.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What happens to the imaginary terms when multiplying the conjugates?

They cancel out

They double

They become real

They remain unchanged

6.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

How do you simplify the expression after multiplying the conjugates?

Divide by the real part

Combine like terms

Subtract the real parts

Add the imaginary parts

7.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the final form of the expression after simplification?

Two separate fractions

An imaginary number

A single complex number

A real number