- #1
Albert1
- 1,221
- 0
$0<\alpha, \beta<\dfrac {\pi}{2}$
prove :$\dfrac {1}{cos^2\alpha}+\dfrac {1}{sin^2\alpha\,sin^2\beta\, cos^2\beta}\geq 9$
and corresponding $\alpha$, and $\beta$
prove :$\dfrac {1}{cos^2\alpha}+\dfrac {1}{sin^2\alpha\,sin^2\beta\, cos^2\beta}\geq 9$
and corresponding $\alpha$, and $\beta$