(Q16)Find the roots of the quadratic equations by applying the quadratic formula.
(i) 2x
2
+ x - 4 = 0
Answer
Comparing this quadratic equation with ax
2
+ bx + c = 0
a = 2; b = 1; c = -4
x =
-b±√(b
2
- 4ac)
2a
=
-1 ± √(1
2
- 4× 2 × (-4))
2 × 2
=
-1 ± √(
+
)
4
=
-1+√
4
or
-1-√
4
Clear