If the equation x2 + 5kx + 16 = 0 has no real roots then

Given the equation x2 + 5kx + 16 = 0 has no real


a = 1 b = 5k c = 16


Thus D = b2 - 4ac < 0


= (5k)2 - 4.1.16 < 0


= 25k2 - 64 < 0


25k2 = 64



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