Quant Question Of The Day: 264
For how many of the following values of k can F( x ) = ( k + 10) x2 + ( k + 10) x – 9 = 0 have equal roots?
(i) −46 (ii) −25 (iii) −10 (iv) −3 (v) 10
A. 1
B. 2
C. 3
D. 0
b2– 4ac must have equal to zero.
i.e , (k + 10)2 = 4(k + 10)(-9)
k = -46 or -10
Howver if k = -10, then f(x) = 0 becomes -9 = 0, which is not possible. Therefore, k can be only – 46.
2. -46 and -10
B
2
C -10
1 value of k = -46
2
B