Question

The value of k for which the roots are real and equal of the following equation

$2x^2$ + kx + 3 = 0 is k = $\pm 2\sqrt{6}$

• A. True
• B. False

Answer 1

The correct option is A True

$2x^2+kx+3=0$

$\Rightarrow$ Here, $a=2,b=k,c=3$

$\Rightarrow$ It is given that roots are real and equal.

$\therefore$ $b^2-4ac=0$

$\Rightarrow$ $(k{)}^2-4(2\left)\right(3)=0$

$\Rightarrow$ $k^2-24=0$

$\Rightarrow$ $k^2=24$

$\Rightarrow$ $k=\pm \sqrt{24}$

$\Rightarrow$ $k=\pm \sqrt{4\times 6}$

$\therefore$ $k=\pm 2\sqrt{6}$

$\therefore$ We can see, value of $k$ given in question is correct.