(ii) x2 + 3x – 2 = 0
Sol. x2 + 3x – 2 = 0
Comparing with ax2 + bx + c = 0 we have a = 1, b = 3, c = –2
b2 – 4ac = (3)2 – 4(1) (–2)
= 9 + 8
= 17
By Formula method,
x
|
=
|
- b ± √(b2 – 4ac)
| ||
2a
| ||||
∴ x
|
=
|
-(3)± √17
| ||
2(1)
| ||||
∴ x
|
=
|
-3 ± √17
| ||
2
| ||||
∴ x
|
=
|
-3+√17
|
or
|
-3-√17
|
2
|
2
|
