SOLUTION: Find all the complex solutions of: x^4+3x^2-4=0

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Question 357892: Find all the complex solutions of:

x^4+3x^2-4=0
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E4%2B3x%5E2-4=0
Use a substitution,
u=x%5E2
u%5E2=x%5E4
u%5E2%2B3u-4=0
%28u%2B4%29%28u-1%29=0
u%2B4=0
x%5E2%2B4=0
x%5E2=-4
highlight%28x=0+%2B-+2i%29
.
.
.
u-1=0
x%5E2=1
highlight%28x=0+%2B-+1%29