(a)

Greatest integer function is also called as floor function

Graph of the function

(i)

(ii)

is does not exist.

Because is exist if and only if their left hand and right hand limits are equal but here

.

(iii)

(b)

(i)        

(ii)  

(c)

We can not determine because a is not an integer

(a)  

(i)   

(ii) Does not exist 

(iii)

(b) 

(i)    

(ii) 

(c) a is not an integer.