If the roots of the quadratic 2x2+kx+2=0 are equal then the value of ′k′ is
Consider the given equations.
2x2+kx+2=0 ……. (1)
Since, the both roots are equals.
Then,
α+α=−k2
2α=−k2
α=−k4
α⋅α=22
α2=1
Therefore,
(−k4)2=1
k216=1
k2=16
k=±4
Hence, this is the answer.