Complex numbers : Finding Square roots of : ExamSolutions

Tutorial on how to find the square roots of complex numbers.

[ExamSolutions_Maths]

Because i equals the root of -1 and so when you square this you get -1... -1 multiplied by b squared gives - b squared. Take a look at my early videos on complex numbers to see these basic results for squaring, cubing etc for values of i.

[peterjhw]

Thank you that was really helpful. Excellently explained, thanks again.

[halimabegum]

I'm not sure. I just wanted an explanation on how to factorise those quartic equations that you did in this video

[trkingdavid]

i like the way u interpret the question

[halimabegum]

Do you have a video up on how to factorise quartic equations?

[chewphuiyee]

Sir, may I know at the beginning part, how did you make that ...+b squared i squared reduced to -b squared?

[BossDropbear]

(a+bi)^2
=(a^2-b^2)+2abi
7-24i
So .. ab=-12 and
(a-b)(a+b)=7
a=-4, b=3 is a solution, as is a=4, b=-3.
i.e. -4+3i, 4-3i.

[farshiddianat]

but if you substitute B= -5, +5 into the first equation (a^2-b^2= -21) you would only get a=2 right?

[IShowAsutoro]

... if I may ask... why isn't b = +/- 2i one of the solutions ?

[lsmith]

why does b have to be a real value 6:40?

[ExamSolutions_Maths]

b is a real number. For example 2i is an imaginary number but the 2 is real

[prachinpatel]

You sir are a legend thank you so much

[APOSTASA]

if i want to find the square root of 1+root of 2 for example can i use a similar method?

[leetong]

why solution for square root of y must be real number ? 6:35 and 11:30

[wdfomfg]

e^ipi = -1, i^2ipi = 1, 4(e^2ipi) = 4

[heishillary]

Can't believe this was uploaded when i was 10 years old

[bournelucid]

Why did the sign not change when the 21b^2 switched sides

[dhvsheabdh]

Sorry, my brother logged into my e-mail account and replied to this. Rest assured, I understood it. Well played sir.

[joycew]

but if you use b=12/a, the answer is ±(4+3i) instead of ±(4-3i)
does it matter? 
:) thanks

[wdfomfg]

Oh okay, and now i noticed i made a typo in the second statement :O that i should be an e....