Write the set of values of 'a' for which the equation x 2 + ax – 1 = 0 has real roots.

Question

Philoid · Accepted Answer

For the quadratic equation to have real roots D 0

Here a = 1, b = a and c = 1

d = b² – 4ac

In the given equation d = a² – 4 ≥ o

D = a ≥ 2

So for all the real values of ‘a’ which are greater than or equal to 2 and – 2 the equation will have the real roots.