Q.
Let k be a real number such that k=0. If α and β are non zero complex numbers satisfying α+β=−2k and α2+β2=4k2−2k, then a quadratic equation having αα+β and βα+β as its roots is equal to
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Complex Numbers and Quadratic Equations
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Solution:
We have α+β=−2k
Also, α2+β2=4k2−2k⇒(α+β)2−2αβ=4k2−2k⇒αβ=k ∴ Sum of roots =αα+β+βα+β=αβ(α+β)2=k4k2=4k
and product of roots =(αα+β)(βα+β)=k4k2=4k
Hence required quadratic equation is x2−4kx+4k=0