Question

Find value of k for which the equation x4+(12k)x2+(k21)=0 has two real solution

Answer 1

let suppose that the equation has two real solution
therefore the condition for real roots
=
$D \: = \sqrt{ {b}^{2} - 4ac } = 0$
here a= 1
b=12k
c=21k


now put these value and get it answer