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Which equation has no real roots (negative discriminant)?

Class 10The Quadratic FormulaQuadratic Equations

A $x^{2} + 2 x + 5 = 0$
B $x^{2} - 2 x + 1 = 0$
C $x^{2} - 5 x + 6 = 0$
D $x^{2} - 4 = 0$

Step-by-Step Solution

For

x^{2} + 2 x + 5 : D = 4 - 20 = - 16 < 0

, so no real roots. The others have

D >= 0

.

Answer: A)

x^{2} + 2 x + 5 = 0

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