Question

50 POINTS! What is the product of complex conjugates? A. The product of complex conjugates is a difference of two squares and is always a real number. B. The product of complex conjugates is the same as the product of opposites. C. The product of complex conjugates is a sum of two squares and is always a real number. D. The product of complex conjugates may be written in standard form as a+bi where neither a nor b is zero. 2) The product (5+i)(5−i) is a real number, 26. What are the factors (5+i) and (5−i) called? A. imaginary numbers B. imaginary units C. complex conjugates D. complex numbers 3) What is the sum of the complex numbers −9−i and −5−i? A. 14+2i B. −14−2i C. −14+2i D. 14−2i 4) What is the product of the complex numbers 8i and 5i? A. 40i B. −40 C. −40i D. 40

Answer 1

see below

Explanation:

What is the product of complex conjugates?

( a+bi) (a-bi)

FOIL

a^2 -abi+abi -b^2i^2

a^2 + b^2

C. The product of complex conjugates is a sum of two squares and is always a real number.

What are the factors (5+i) and (5−i) called?

These are called complex conjugates because the imaginary parts are opposites

C. complex conjugates

What is the sum of the complex numbers −9−i and −5−i?

-9-i+-5-i

Add the real parts

-9-5 = -14

Add the imaginary parts

-i-i = -2i

-14-2i

B. −14−2i

What is the product of the complex numbers 8i and 5i?

8i*5i = 40 i^2

We know that i^2 = -1

40*-1 = -40

B. −40