BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

nonzero roots

Expert replies
by sanju09 » Tue Mar 03, 2009 5:03 am
If a and b are the nonzero roots of the quadratic equation x^2 + a x + b = 0, then
A. a = 1 and b = −4
B. a = 1 and b = −2
C. a = −1 and b = −4
D. a = −1 and b = 2
E. a = −1 and b = 4
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Join the discussion
Source: — Problem Solving |

by bluementor » Tue Mar 03, 2009 5:44 am
x^2 + a x + b = 0 (Eqn 1)

a and b are the nonzero roots:
(x-a)(x-b)=0
x^2 -ax -bx + ab = 0
x^2 -(a+b)x + ab = 0 (Eqn 2)

Comparing equations 1 and 2:

Product of both roots = b
ab = b
a=1

Sum of both roots = -a
a + b = -a
2a = -b
b = -2

Choose B

-BM-
Join the discussion