Multiplying Complex Numbers

[nycmathguy]

Section 2.4
32 & 34

Question 32

(7 - 2i)(3 - 5i)

21 - 35i - 6i + 10i^2

21 - 41i + 10(-1)

21 - 41i - 10

11 - 41i

Question 34

-8i(9 + 4i)

-72i - 32i^2

-72i - 32(-1)

-72i + 32

Switch the terms.

32 - 72i

You say?

 

[MathLover1]

perfect

 

[nycmathguy]

perfect

Good chapter so far. Keep in mind that precalculus is a review for me, a return to MA172.