Which notation expresses the number of permutations of 9 items taken 8 at a time?

answer: -8.2562234e+13

σк тнє αиѕωєя ιѕ (α.)

нσρє ι ¢συℓ∂ нєℓρ υ

place r′ so that qr′ is parallel to the tangent.

now we get that ∠r′py=∠pr′q, where y is on the tangent, on the opposite side of p from x.

also, because of the symmetry, ∠r′py=∠qpx.

finally, note that no matter where we place r, as long as it's on the correct arc, we have ∠prq=∠pr′q.

stringing all these equalities together, we end up with ∠prq=∠qpx.

this picture will show how its going to look like.

hope this by jack monhen