Question

Write the set of value of 'a' for which the equation x² + ax − 1 = 0 has real roots.

Answer 1

SOLUTION :  

Given : x² + ax - 1 = 0

On comparing the given equation with ax² + bx + c = 0  

Here, a = 1 , b = a , c = -  1)

D(discriminant) = b² – 4ac

D = a² - 4 × 1( -1)

D = a² + 4

D = a² + 4 ≥0

Given equation has real roots , i e D ≥ 0

Since, D ≥ 0 , so given equation has real value of a

Hence, for all real value of ‘a’  the given equation has real roots.

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Answer 2

Answer:

Step-by-step explanation: