Question

solve for (a+bi)^3 dealing with complex numbers

Answer 1

(a+bi)(a+bi)(a+bi)

do it like normally; the i's are just another variable in this case.

when you get to the end....anything that has an i^2 is multiplied by -1

Answer 2

i think the problem that i have is that they are not numbers so it messes me up but i have to foil all this right

Answer 3

yeah foil it , and dont be intimidated by that i..... own it :)

Answer 4

(a+bi)(a+bi)

(a^2 +2abi +(bi)^2)
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(a+bi)(a^2 +2abi +(bi)^2)

a^3 +3a^2bi +3a(bi)^2 + (bi)^3 .... if I did it right :)

Answer 5

a^3 +3a^2b(i) +3ab^2(i^2) +b^3(i)(i^2)

a^3 +3a^2b(i) -3ab^2 -b^3(i)

a^3 -3ab^2 +3a^2b(i) -b^3(i) looks about right

Answer 6

but if im wrong, let me know ;)

Answer 7

well im not exactly sure how to enter in cause it gives (a+bi)^3=box+box i

Answer 8

I think I see a solution to the problem :)

Answer 9

[ a(a^2 +3b^2) ] box1 + [ b(3a^2 - b^2) ] box2 [i]

Answer 10

ok ill see thanks