If 2x2 + 5x + 1 = 0, then one of the values of x - is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e.
2x2 + 5x + 1 = 0
On dividing the above equation by 2x we get,
x + 5/2 + 1/2x = 0
x + 1/2x = -5/2
As we know that,
(a - b)2 = (a + b)2 - 4ab
(x - 1/2x)2 = (x + 1/2x)2 - 4 × x × 1/2x.
(x - 1/2x)2 = -5/2 × -5/2 - 2
(x - 1/2x) = .