If -4 is a root of the equation x2 +px -4=0 and the equation 2x2 +px +k=0 has equal roots find 'k'If -4 is a root of the equation x2 +px -4=0 and the equation 2x2 +px +k=0 has equal roots find 'k'
If -4 is the root of the eqn x2 + px -4 = 0
=> x = 14
=> -4 x -4 + p x -4 -4 = 0
=> 16 - 4p - 4 = 0
=> -4p = -12
=> p = 3
Now, second eqn has equal roots
=> b2 - 4ac = 0
=> p2 - 8k = 0
=> -8k = -9
=> k = 9/8
I am not sure about the calculation, so plz check it out again, otherwise the procedure is correct :D
=> x = 14
=> -4 x -4 + p x -4 -4 = 0
=> 16 - 4p - 4 = 0
=> -4p = -12
=> p = 3
Now, second eqn has equal roots
=> b2 - 4ac = 0
=> p2 - 8k = 0
=> -8k = -9
=> k = 9/8
I am not sure about the calculation, so plz check it out again, otherwise the procedure is correct :D