1. ## Limite

Hi eveybody,

i must calculate the following limit:

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

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

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

2. First note that $1 - \sin^2 x = cos^2 x$ which should help cancel out some of the cosines on the bottom.