Limit X tends to 0
8/X^8(1-CosX^2/2-CosX^2/4+Cos X^2.CosX^2/4)
Limit tends to π/2
Arc Cos[Cot X]
Where [ .] Represents greatest integer X
Limit X tends to infinity
(X+C/X-C)^x=4
Then find C