The value of m for which the function f(x) = , is differentiable at x = 1, is
0
1
2
does not exist
For the function f(x) = x2 - 6x + 8, , the value of x for which f'(x) vanishes, is
9/4
5/2
3
7/2
The function f(x) = cot-1(x) + x, increases in the interval
C.