Multiplying complex numbers (HELP!!)
\[\left( \sqrt{3 }i \right) \left( \sqrt{-3}i \right) - \sqrt{3}i (2-\sqrt{-3})\]
Please show work :(
\[\Large \left( \sqrt{3 }\;i \right) \color{royalblue}{\left( \sqrt{-3}\;i \right)} - \sqrt{3}\;i (2-\sqrt{-3})\] \[\Large \left( \sqrt{3 }\;i \right) \color{royalblue}{\left( \sqrt{3}\;i^2 \right)} - \sqrt{3}\;i (2-\sqrt{-3})\]
Do you understand what I did in that step there?
Oh because you took out the negative in the radical and added that i to the other one
Multiplied the i's together :) Yes.
If we multiply the first 2 brackets together we get, \[\Large 3\;i^3 - \sqrt{3}\;i (2-\sqrt{-3})\](multiply the 3's together and then the i's with one another)
Ok, i follow. and the last term (before any multiplication) in the equation becomes minus radical 3i?
ya that's a good idea probably.\[\Large 3\;i^3 - \sqrt{3}\;i (2-\sqrt{3}\;i)\]
Distributing the sqrt3i to each term in the brackets is going to be a little messy. Do you think you can do it? :D
Ill work it right now. Thanks so much btw!! @.@
...and i already have a question... when distributing, does the two multiply the three (becoming radical 6i) or does it become 2 radical 3i
\[\Large\bf\sf \sqrt2\cdot \sqrt3\quad=\quad \sqrt{2\cdot3}\quad=\quad \sqrt6\] \[\Large\bf\sf 2\cdot \sqrt3\quad\ne\quad \sqrt6\]\[\Large\bf\sf 2\cdot \sqrt3\quad=\quad 2\sqrt3\]
Can more be done?
Did you distribute the thing to the second term as well? Yes, lots more can be done ^^
\[3i ^{3}-2\sqrt{3}i + \sqrt{6}i ^{2}\]
9 my bad
Ah good fix.
then 3
-3 times -2 so +6?
\[\Large 3i ^{3}-2\sqrt{3}i + 3i ^{2}\]
just -3....final answer
whut? XD
\[i ^{2}= -1 \]
Oh for the last term? Ah good.
so 3 times -1 equals -3?
Ya we can simplify our last term using that, \[\Large 3i ^{3}-2\sqrt{3}i -3\]
Do you know how to simplify i^3?
sorta... i^2 times i equals -1 times i so it simplifies to negative i?
yesss good.\[\Large -3i-2\sqrt{3}i -3\]
And from here, I'm not really sure how we want to leave our answer. Does your teacher want it in the form `a+bi` ?
I would assume so yes...is this the answer? No more could be done?
Well that is a fine answer, yes. But if your teacher wants it in the form a+bi, then we should rewrite the real part first, and also factor an i out of each imaginary part.\[\Large -3+(-3-2\sqrt3)i\]See how it's in the form,\[\Large a+(b)i\]now?
I do! Oh my god you dont know how much this helped. You are a god among men! A thousand thank yous! <3
lol np \c:/
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