Q.

Let [x] denote the greatest integer function, and let m and n respectively be the numbers of the points, where the function f(x)=[x]+|x2|,2<x<3, is not continuous and not differentiable Then m + n is equal to :          [2025]

1 7  
2 8  
3 6  
4 9  

Ans.

(2)

Given : f(x)=[x]+|x2|,2<x<3

The function can also be written as follows:

f(x)={x,2<x<1x+1,1x<0x+2,0x<1x+3,1x<2x,2x<3

Here, function f(x) is not continuous at x = –1, 0, 1 and 2.

Hence, function f(x) is not differentiable at x = –1, 0, 1 and 2.

So, we have m = n = 4.

   m + n = 4 + 4 = 8.