±16
±8
±4
±2
Correct answer is C
2x2+kx+5=0
α+β=−ba=−k2
αβ=ca=52
α2+β2=(α+β)2−2αβ
−1=(−k2)2−2(52)
−1=k24−5⟹k24=4
k2=16∴
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