Find all roots of the equations

(a) z^4 + 2z^2 + 4 = 0

My step:

Let u = z^2

u^2 + 2u + 4 = 0

u = -1 + (3)^1/2 and u = -1 - (3)^1/2

i'm stuck at there...and tomorrow having complex number exam.

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- May 6th 2010, 02:27 AMwkn0524Revision-complex number
Find all roots of the equations

(a) z^4 + 2z^2 + 4 = 0

My step:

Let u = z^2

u^2 + 2u + 4 = 0

u = -1 + (3)^1/2 and u = -1 - (3)^1/2

i'm stuck at there...and tomorrow having complex number exam. - May 6th 2010, 02:50 AMHallsofIvy
- May 6th 2010, 02:59 AMwkn0524