- #1

- 13

- 0

## 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.

Last edited: