Book: RS Aggarwal - Mathematics
Chapter: 10. Quadratic Equations
Subject: Maths - Class 10th
Q. No. 27 of Exercise 10C
Listen NCERT Audio Books - Kitabein Ab Bolengi
27
Find the roots of each of the following equations, if they exist, by applying the quadratic formula:
x2 – 2ax – (4b2 – a2) = 0
Given: x2 – 2ax – (4b2 – a2) = 0
Comparing with standard quadratic equation Ax2 + Bx + C = 0
A = 1, B = – 2a, C = – (4b2 – a2)
Discriminant D = B2 – 4AC
= (– 2a)2 – 4.1. – (4b2 – a2)
= 4a2 – 4a2 + 16 b2 = 16b2 > 0
Hence the roots of equation are real.
Roots 
are given by
x = (a + 2b) or x = (a – 2b)
Hence the roots of equation are (a + 2b) or (a – 2b)
