4u complex no (1 Viewer)

jnney · Jul 23, 2011

find the three cube roots of each of the following in the form a+ib, where a, b are real

a)1

b)-64

c)1/8

jnney · Jul 23, 2011

never mind i understand.

maths lover · Jul 23, 2011

why all the prelim guys starting 4unit i feel like i am behind now.

Aysce · Jul 23, 2011

Nearly year 12 plus complex numbers are fun (Y)

ohexploitable · Jul 23, 2011

umm these are really basic questions what should have worked examples in the textbooks

e.g a)

$\\z=\sqrt[3]{1}\\z^3=1\\z^3-1=0\\(z-1)(z^2+z+1)=0\\z=1,\, z^2+z+\frac{1}{4}+\frac{3}{4}=0\\(z+\frac{1}{2})^2-\frac{3}{4}i^2=0\\(z+\frac{1}{2}-\frac{\sqrt{3}}{2}i)(z+\frac{1}{2}+\frac{\sqrt{3}}{2}i)=0$

$\therefore z=1,\,-\frac{1}{2}\pm\frac{\sqrt3}{2}i$

Alkanes · Jul 23, 2011

Get cracking then

4u complex no (1 Viewer)

jnney

lemon

jnney

lemon

maths lover

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Aysce

Well-Known Member

ohexploitable

hey

Alkanes

Active Member

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