Solutions:
$\left( i \right)\text{ }2{{x}^{2}}~+~kx~+\text{ }3\text{ }=\text{ }0$
Comparing the given equation with $a{{x}^{2}}~+~bx~+~c~=\text{ }0$ , we get,
$a~=\text{ }2,~b~=\text{ }k\text{ }and~c~=\text{ }3$
As we know, Discriminant $=~{{b}^{2}}~\text{ }4ac$
$=\text{ }{{\left( k \right)}^{2}}~\text{ }4\left( 2 \right)\text{ }\left( 3 \right)$
$=~{{k}^{2}}~\text{ }24$
For equal roots, we know,
Discriminant = 0
${{k}^{2}}~\text{ }24\text{ }=\text{ }0$
${{k}^{2}}~=\text{ }24$
$k\text{ }=\text{ }\pm \surd 24~=\text{ }\pm 2\surd 6$
$\left( ii \right)~kx\left( x~\text{ }2 \right)\text{ }+\text{ }6\text{ }=\text{ }0$
$or~k{{x}^{2}}~\text{ }2kx~+\text{ }6\text{ }=\text{ }0$
Comparing the given equation with $a{{x}^{2}}~+~bx~+~c~=\text{ }0$ , we get
$a~=~k,~b~=\text{ }\text{ }2k~and~c~=\text{ }6$
We know, Discriminant $=~{{b}^{2}}~\text{ }4ac$
$=\text{ }{{\left( \text{ }\text{ }2k \right)}^{2}}~\text{ }4\text{ }\left( k \right)\text{ }\left( 6 \right)$
$=\text{ }4{{k}^{2}}~\text{ }24k$
For equal roots, we know,
${{b}^{2}}~\text{ }4ac~=\text{ }0$
$4{{k}^{2}}~\text{ }24k~=\text{ }0$
$4k~\left( k~\text{ }6 \right)\text{ }=\text{ }0$
$Either\text{ }4k~=\text{ }0\text{ }or~k~=\text{ }6\text{ }=\text{ }0$
$k~=\text{ }0\text{ }or~k~=\text{ }6$
However, if k = 0, then the equation will not have the terms ‘x2‘ and ‘x‘.
Therefore, if this equation has two equal roots, k should be 6 only