Lim x-->infinity [ (x-pie/2)/cosx]
where  is greatest int function
lim x-->pie/2 [sinx]
again [.] is greatest int function
Also last one
Lim x--> infinity Sec^-1(x/(x+1))
In this last one why can't we divide number and denom in the paramenters of sec^-1 by x?
Small sums only. Please solve @Churchil_Dwivedi and others