Question

If the discriminant of the quadratic equation 4$x^2$ + px + 25 = 0 is 0, what is the value of p if p $>$ 0?

• A. 10
• B. 20
• C. 30
• D. -20

Answer 1

The correct option is B

20

4$x^2$ + px + 25 = 0

a = 4, b = p and c = 8.

Discriminant, D = $b^2-4\times a\times c$

$\Rightarrow$ $p^2-4\times 4\times 25=0$

$\Rightarrow$ $p^2-400=0$

$\Rightarrow$ p = 20, –20

Since, its given that p $>$ 0

p = 20