Question

What is the value of the product (3 – 2i)(3 + 2i)? A. 5 B. 9 + 4i C. 9 – 4i D. 13

Answer 1

Answer:

D. 13

Step-by-step explanation:

You can do the product in the straight-forward way ...

... (3 -2i)(3 +2i) = 3·3 +3·2i -3i·3 -(2i)(2i)

... = 9 +6i -6i -4i² . . . . . note the middle two terms cancel

Recognize that i = √-1, so i² = -1. Then the sum is

... = 9 -4(-1) = 9+4 = 13

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Your graphing calculator can do this product, too.

Answer 2

Answer:

13

Step-by-step explanation:

3²-(2i)²

=9-(4*-1)

=9-(-4)

=9+4

=13