Q.

Let f(x)=[x2-x]+|-x+[x]|, where x and [t] denotes the greatest integer less than or equal to t. Then, f is:         [2023]

1 continuous at x=0, but not continuous at x=1  
2 continuous at x=0 and x=1  
3 not continuous at x=0 and x=1  
4 continuous at x=1, but not continuous at x=0  

Ans.

(4)

We have, f(x)=[x2-x]+|-x+[x]|

=[x(x-1)]+|-x+x-{x}|

f(x)=[x(x-1)]+{x}

f(0+)=-1+0=-1 R.H.L.=f(1+)=0+0=0
f(0)=0 f(1)=0 
  L.H.L.=f(1-)=-1+1=0

 

  f(x) is continuous at x=1, and discontinuous at x=0.