Question

If xy = 10 then minimum value of 12x²+ 13y² is equal to –

• A. 15
• B. $40\sqrt{39}$
• C. $3\sqrt{13}$
• D. $30\sqrt{13}$

Answer 1

Answer: (B)

$40\sqrt{39}$

Answer 2

$\frac{12x^{2} + 13y^{2}}{2}$³ $\sqrt{(12x^{2})(13y^{2})}$

̃ 12x² + 13y² ³ $40\sqrt{39}$min.