Question

Choose the correct statement to correct the following if required for 2x(2)+bx+8=0 to have non real roots. A) -8

Answer 1

Answer:

The correct answer is a) -8<b<8

Explanation:

We have, for non-real roots,

D < 0

i.e. b^2 - 4ac < 0

Þ b ^2 - 64 < 0

b ^2 < 64

b < +- 8

b < 8 and b > - 8

- 8 < b < 8.

Hope it helps..!!

Answer 2

The non real roots lies in - 8 < b < 8.

Explanation:

The given quadratic equation:

$2x^2+bx+8=0$

Here, a = 2, b = - b and c = 8

To find, the non real roots of b = ?

The condition for non real roots of the quadratic equation

D < 0

$=b^2-4ac<0$

⇒ $b^2-4(2)(8)<0$

⇒ $b^2-64<0$

⇒ $b^2<64$

⇒ b < ±  8

⇒ b < 8 and b > - 8

⇒ - 8 < b < 8

Hence, the non real roots lies in - 8 < b < 8.