(iii) x2 + (x – 1)/3 = 0
Sol. x2 + (x – 1)/3 = 0
Multiplying the above equation by 3, we get
3x2 + x – 1 = 0
Comparing with ax2 + bx + c = 0 we have a = 3, b = 1, c = – 1
b2 – 4ac = (1)2 – 4 (3) (– 1)
= 1 + 12
= 13
By Formula method,
x
|
=
|
- b ± √(b2 – 4ac)
| ||
2a
| ||||
∴ x
|
=
|
-1 ± √13
| ||
2(3)
| ||||
∴ x
|
=
|
-1 ± √13
| ||
6
| ||||
∴ x
|
=
|
-1+√13
|
or
|
-1-√13
|
6
|
6
|