Question

If one root of the equation x²+ px + 12 = 0 is 4, while the equation x² + px + q = 0 has equal roots, the value of q is:

विकल्प

• `49/4`

• `4/49`

• 4

• 49

Answer 1

`49/4`

Explanation:

Since 4 is a root of x² + px + 12 = 0

∴ (4)² + p(4) + 12 = 0

⇒ p = −7

Also the roots of x² + px + q = 0 are equal, we have p² – 4 × 1 × q = 0

⇒ (−7)² − 4q = 0

∴ q = `49/4`