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Mathematics 7 Online
OpenStudy (studygurl14):

Pre-calculus. PLEASE HELP! MEDAL! @Directrix @SolomonZelman @e.mccormick

OpenStudy (studygurl14):

OpenStudy (solomonzelman):

you can use pascals triangle to expand it (or wolfram) or first find what \(\large\color{slate}{ (-2-2i)^2 }\) is, and then raise that to the second power.

OpenStudy (studygurl14):

If I do that, I get -64. Which isn't an answer choice. This has to do with polar equation, complex numbers, etc.

OpenStudy (solomonzelman):

you say isn't an answer choice?

OpenStudy (studygurl14):

oops, sorry it is an answer choice.

OpenStudy (studygurl14):

lo, sorry looking at the wrong problem.

OpenStudy (solomonzelman):

I doubt it would be -64 though

OpenStudy (studygurl14):

Stupid me. :( Anyway, thanks. :)

OpenStudy (studygurl14):

Yeah, I feel like it should be a or c, but I don't know how to get that

OpenStudy (solomonzelman):

what I would do for convenience. \(\large\color{slate}{ (-2-2i)^4 }\) \(\large\color{slate}{ ((-1)(2+2i))^4 }\) \(\large\color{slate}{ (-1)^4(2+2i)^4 }\) \(\large\color{slate}{ (2+2i)^4 }\)

OpenStudy (solomonzelman):

\(\large\color{slate}{ (2+2i)^4 }\) \(\large\color{slate}{ \left(~\color{red}{(2+2i)^2}\right)^2 }\) applying `(a+b)^2=(a^2+2ab+b^2)` to the red part \(\large\color{slate}{ \left(~\color{red}{2^2+2(2)(2i)+(2i)^2}\right)^2 }\) \(\large\color{slate}{ \left(~\color{red}{4+8i+(-4)}\right)^2 }\) \(\large\color{slate}{ \left(~\color{red}{8i}\right)^2 }\)

OpenStudy (solomonzelman):

yes, your answer was correct actually

OpenStudy (solomonzelman):

I just was thinking that there will always be a middle term with i's and a constant near, but the constant in last and first term cancel each other

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