1.

If the equation x2 + 4x + k = 0 has real and distinct roots, then.(A) k < 4(B) k > 4(C) k ≥ 4(D) k ≤ 4

Answer»

The correct answer is (A) k < 4.

The given equation is x2 + 4x + k = 0

Here, a = 1, b = 4 and c = k

D = b2 – 4ac

= (4)2 – 4 x 1 x k

= 16 – 4k

The given equation will have real and distinct roots, if

D > 0

16 – 4k > 0

16 > 4k

4k < 16

k < 16/4

k < 4



Discussion

No Comment Found