b² - 4ac < 0
(-5)² - 4(2)(k - 6) < 0
25 - 8k + 48 < 0
-8k + 73 < 0
-8k < -73
k > 73/8
(-5)² - 4(2)(k - 6) < 0
25 - 8k + 48 < 0
-8k + 73 < 0
-8k < -73
k > 73/8
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If it has no real roots, the discriminant b^2 - 4ac is less than 0.
a = coefficient of x^2 = 2
b = coefficient of x = -5
c = constant term = k - 6
So (-5)^2 - 4*(2)(k - 6) < 0
Solve that inequality for k.
a = coefficient of x^2 = 2
b = coefficient of x = -5
c = constant term = k - 6
So (-5)^2 - 4*(2)(k - 6) < 0
Solve that inequality for k.