Hi eveybody,

i must calculate the following limit:

$\displaystyle \forall n\in \mathbb{N}*,$ $\displaystyle F_n$ is the function that is defined as follows:

$\displaystyle \lim_{x\to \frac{\pi}{2}} F_n(x)=\frac{(1-sinx)(1-sin^2x)...(1-sin^nx)}{cos^{2n}x}$

I don't know what to do? (use substitution?)

Can you help me please

And thank you anyway.