defence exam Coast Guard Navik GD (General Duty) 02/2025 Mock Test Series Mathematics Differential Calculus Applications of Derivatives
यदि 5f(x) + 4f\(\rm \left(\frac{1}{x}\right)\)= x2 - 2, सभी x ≠ 0 के लिए और y = 9x2f(x) है, तो y किस अंतराल में निरंतर वर्धमान है?
1
\(\rm \left(0,\frac{1}{\sqrt5}\right)\cup\left(\frac{1}{\sqrt5}, \infty\right)\)
2
\(\rm \left(-\frac{1}{\sqrt5},0\right)\cup\left(\frac{1}{\sqrt5}, \infty\right)\)
3
\(\rm \left(-\frac{1}{\sqrt5},0\right)\cup\left(0,\frac{1}{\sqrt5}\right)\)
4
\(\rm \left(-\infty,\frac{1}{\sqrt5}\right)\cup\left(0,\frac{1}{\sqrt5}\right)\)