Ch¢teaux is the French word to describe a country or manor house. You would not therefore expect to find a ch¢teaux in a city. However, in Canada, a ch¢teau normally denotes a hotel and Ch¢teau Frontenac is the name for a very grand hotel in Quebec.

d/dx(cos x)

= -sinx

Use the power/chain rules:

d/dx (2 cos2 x) = 2 d/dx (cos x)2 = (4 cos x)*d/dx(cos x) = -4 cos x sin x = -2 sin 2x

Cos it is :D but thats good, cos then people can travel around the country more easily, and travel is not that long either :D