- #1
Sensayshun
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Homework Statement
[tex]2iz^2 - (3-8i)z -6 + 7i[/tex]
Homework Equations
[tex]z = \frac{-b +/- \sqrt{b^2 - 4ac}}{2a}[/tex]
The Attempt at a Solution
Right, here goes...
a = 2i
b = -3 + 8i (is this correct? Or would it be better to leave it as 3-8i?)
c = (-6 + 7i)
so using these:
z = [tex]\frac{3-8i) +/- \sqrt{(-55-48i) - (4(2i(-6 + 7i))}}{4i}[/tex]
I'll just work with the top line for now to make writing it easier.
But that last section under the square root, simplifies to:
[tex]\sqrt{(-55 - 48i) - (48i + 56)}[/tex]
which is then:
[tex]\sqrt{-111 - 96i}[/tex]
THIS IS WHERE I THINK I START TO GET STUCK
Do I then take the complex conjugate of the bottom to give:
[tex]\frac{(3 - 8i)(-4i)}{(4i)(-4i)} +/- \frac{\sqrt{111 - 96i}}{4i}[/tex]
multiplying this out gives:
[tex]\frac{-3}{4}i - 2 +/- \frac{\sqrt{111 - 96i}}{4i}[/tex]
and then I'm not sure where to go from here, or if I've headed in the correct direction
Thanks for any help given.
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