Math Q. Paper Doubt

Q: If z³+(3+2i)z+(ai-1) = 0 has a real root, then ' a ' lies in the interval (a Îµ R) :

My Ans: (-1,0) , Given answer (-2,3)

2 Answers

262

Aditya Bhutra ·2012-02-21 22:34:16

(z³ +3z -1) +i(2z+a) =0

for real root , 2z+a =0 and z³ +3z -1=0

from the above eqns , your answer seems correct.

Hmm. Thanks!

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