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Question
Without actually determining the roots comment upon the nature of the roots of each of the following equations:
x2 + 5x + 15 = 0.
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Solution
x2 + 5x + 15 = 0
Here, aa= 1, b = 5 and c = 15
D = b2 - 4ac
= (5)2 - 4 x 1 x 15
= 25 - 60
= -35
⇒ D < 0
roots are imaginary.
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