"Complex Roots always come in pairs" (1 Viewer)

ProdigyInspired

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I'm doing a question where

(2-i)z2 - (1+i)z + 1 = 0

One of the roots is i,

therefore the other one should be the conjugate of i -> -i, isn't it?

But putting in -i doesn't give me 0.

I check Wolfram Alpha and it is an entirely separate number, how do I solve this?
 

braintic

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I'm doing a question where

(2-i)z2 - (1+i)z + 1 = 0

One of the roots is i,

therefore the other one should be the conjugate of i -> -i, isn't it?

But putting in -i doesn't give me 0.

I check Wolfram Alpha and it is an entirely separate number, how do I solve this?
Once you see that one of the roots is i, it is much easier to use sum or product of roots than to use the quadratic formula.
 

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