SOLUTION: solve the expressions (2-i)^3 in form of a+bi

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Question 212480: solve the expressions (2-i)^3 in form of a+bi
Found 2 solutions by stanbon, drj:
Answer by stanbon(48545) About Me  (Show Source):
You can put this solution on YOUR website!
solve the expressions (2-i)^3 in form of a+bi
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(2-i) = 2^3 + 3*2^2(-i) + 3*2*(-i)^2 + (-1)^3
= 8 -12i -6 + i
---
= 2 - 13i
=================
Cheers,
Stan H.

Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the expression


%282-i%29%5E3 in form of a+bi


Step 1. Multiply first the following using the FOIL technique:

%282-i%29%282-i%29=4-4i%2Bi%5E2 but i%5E2=-1. So


%282-i%29%282-i%29=4-4i%2B%28-1%29


%282-i%29%282-i%29=3-4i


Step 2. Now multiply 3-4i by 2-i to get (2-i)^3. Using the FOIL method, we have


%282-i%29%5E3=%283-4i%29%282-i%29=6-11i%2B4i%5E2


%282-i%29%5E3=6-11i-4

%282-i%29%5E3=2-11i ANSWER


Hope the steps were helpful. Good luck in your studies.

Respectfully,
Dr J

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