Question

If 1/2 is the root of the equation x²+kx-5/4 then find the value of k.

Answer 1

p(x) = x^2 + kx - 5/4 = 0
p(1/2)  =  1/4 + k/2 - 5/4  = 0
            = 1+2k-5  / 4 = 0
            = -4 + 2k = 0   
            = 2k = 4 
            =   k = 2

Answer 2

Given 1/2 is a ropt of eq
X^2+Kx-5/4...
So,
By putting X=1/2 in this eq.. we get,

(1/2)^2 +K ×1/2 -5/4=0
1/4+K/2-5/4=0

1+2k-5/4=0
-4+2k/4=0
-4 +2k=0
2k=4
K=2..