Book: RS Aggarwal - Mathematics
Chapter: 10. Quadratic Equations
Subject: Maths - Class 10th
Q. No. 17 of Exercise 10C
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17
Find the roots of each of the following equations, if they exist, by applying the quadratic formula:
2x2 + ax – a2 = 0
Given: 2x2 + ax – a2 = 0
Comparing with standard quadratic equation Ax2 + Bx + C = 0
A = 2, B = a, C = – a2
Discriminant D = B2 – 4AC
= (a)2 – 4.2. – a2
= a2 + 8 a2 = 9a2 ≥0
Hence the roots of equation are real.
Roots 
are given by
Hence the roots of equation are 
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