If ½ is a root of the equation

Question

If ½ is a root of the equation $x ² + k x - 5 / 4 = 0$ , then the value of k is

Smart Achievers · Accepted Answer

(1)

$G i v e n e q u a t i o n : x ² + k x - 5 / 4 = 0 . S i n c e ½ i s a r o o t, (½) ² + k ½ - 5 / 4 = 0 \Rightarrow 1 / 4 + k / 2 - 5 / 4 = 0 \Rightarrow k / 2 - 1 = 0 \Rightarrow k = 2$

Solution

Q.
If ½ is a root of the equation $x ² + k x - 5 / 4 = 0$ , then the value of k is

1 2

2 -2

3 1/4

4 1/2

Ans.
(1)

$G i v e n e q u a t i o n : x ² + k x - 5 / 4 = 0 . S i n c e ½ i s a r o o t, (½) ² + k ½ - 5 / 4 = 0 \Rightarrow 1 / 4 + k / 2 - 5 / 4 = 0 \Rightarrow k / 2 - 1 = 0 \Rightarrow k = 2$

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