Question

For waht value/s of p, the quadratic equation $3x^2-px+4=0$ has real and equal roots?

• A. $2\sqrt{3}$
• B. $4\sqrt{3}$
• C. $\pm 4\sqrt{3}$
• D. $-4\sqrt{3}$

Answer 1

The correct option is C $\pm 4\sqrt{3}$

$3x^2-px+4=0$

$a=3,b=-p,c=4$

Since the quadratic equation has real and equal roots,

$D=b^2-4ac=0$

$(-p{)}^2-4\times 3\times 4=0$

$p^2-48=0$

$p^2=48\Rightarrow p=\pm 4\sqrt{3}$

$\text{(c) is corrrect}$