Multiplying complex numbers | Imaginary and complex numbers | Precalculus | Khan Academy

Multiplying Complex Numbers

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Precalculus on Khan Academy: You may think that precalculus is simply the course you take before calculus. You would be right, of course, but that definition doesn't mean anything unless you have some knowledge of what calculus is. Let's keep it simple, shall we? Calculus is a conceptual framework which provides systematic techniques for solving problems. These problems are appropriately applicable to analytic geometry and algebra. Therefore....precalculus gives you the background for the mathematical concepts, problems, issues and techniques that appear in calculus, including trigonometry, functions, complex numbers, vectors, matrices, and others. There you have it ladies and gentlemen....an introduction to precalculus!

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[TheJpdragon]

i strug;e w/ mathematics in specific imaginary numbers this helped alot thanks

[masonbxls]

you explain this so much better than my teacher. glad i found this.

[marchanselthomas]

I can't emphasize enough how much of an impact this guy is making!

[sanzherharsha]

Your so Brilliant thank u for making me understand this topic

[areallemone]

thanks so much, had fallen behind, this is very useful

[Ra-lbio]

When u decide to get a headstart during summer break on maths just bc u know u can trust khan academy

[brilliantmwewa]

I finally understand this all thanks to you 😘😘

[otiscarr]

excellent trick factorising it, first time i've seen it.

[Dead_Leelee]

So, i times i is always -1 for every multiplying complex number question, am I right?

[slimeslayer]

just cramming for finals at 1:30 in the morning

[loganaaron]

What if there is a # before the first set of Parentheses. Ex: 4i (2+5i)(2- i)

[ghadahalqahtani]

What if (3+6i)^2
I really need to know please

[dawoodibrahim]

Someone please explain this to me
(a, b) (c, d)= (ac-bd, ad+bc)

[rhnwefz]

so much better then that raspy McWhorter...

[tobiadedoyin]

In other words, i^2 does exactly what the minus sign does in a multiplication question.

[kaileeanderson]

can you guys do a video on Literal Equations I just DON'T UNDERSTAND!!

[PotatofridgeMonster]

Can someone solve this for me

(a+bi)*(a-bi)=4