Question

If the roots of the equation 12x² + mx + 5 = 0 are in the ratio 3 : 2, then m equals –

• A. 1/12
• B. 5/12
• C. ± 5 $\sqrt{10}$
• D. ± 5 $\sqrt{10/12}$

Answer 1

Answer: (C)

± 5 $\sqrt{10}$

Answer 2

$\frac{b^{2}}{ac}$ =$\frac{(m + n)^{2}}{mn}$

⇒ $\frac{m^{2}}{60}$ =$\frac{(3 + 2)^{2}}{3.2}$

⇒ m² = 250

⇒ m = ± 5$\sqrt{10}$