Question

The discriminant of x²–3x–k=0 is 1. A value of x is .......,select a proper option (a), (b), (c) or (d) from given options so that the statement becomes correct.
(a) -4
(b)-2
(c) 2
(d) 4

Answer 1

answer is option no. (c) 2

Answer 2

Option ( b ) is correct.

Explanation :

Compare given Quadratic equation

x² - 3x - k = 0 with ax² + bx + c = 0,

a = 1 , b = -3 , c = -k,

Discreminant ( ∆ ) = 1 [ given ]

b² - 4ac = 1

=> ( -3 )² - 4×1×(-k) = 1

=>9 + 4k = 1

=> 4k = 1 - 9

=> 4k = -8

=> k = ( -8 )/4

=> k = -2

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