(i) m2 – 3m – 10 = 0
Sol. m2 – 3m – 10 = 0
Comparing with am2 + bm + c = 0 we have a = 1, b = –3, c = –10
b2 – 4ac = (– 3)2 – 4 (1) (–10)
= 9 + 40
= 49
By Formula method,
m
|
=
|
- b ± √(b2 – 4ac)
| ||
2a
| ||||
∴ m
|
=
|
-(-3)± √49
| ||
2(1)
| ||||
∴ m
|
=
|
3 ± 7
| ||
2
| ||||
∴ m
|
=
|
3+7
|
or
|
3-7
|
2
|
2
| |||
∴ m
|
=
|
10
|
or
|
-4
|
2
|
2
| |||
∴ m
|
=
|
5
|
or
|
-2
|
