The set of points where the function `f(x)=x|x|` is differentiable is (a) `(-oo,\ oo)` (b) `(-oo,\ 0)uu(0,\ oo)` (c) `(0,\ oo)` (d) `[0,\ oo]`

The set of points where the function f(x)=x|x| is differentiable is (-oo,oo) (b) (-oo,0)uu(0,oo) (0,oo) (d) [0,oo)

The set of points where the function f(x)=x|x| is differentiable is (-oo,oo)(b)(-oo,0)uu(0,oo)(0,oo)(d)[0,oo)

The function f(x)= (x)/(1+|x|) is differentiable on (A) (0 oo) 0 oo) (B) (-oo 0) (C) (D) all the above

The function f(x)=cot^(-1)x+x increases in the interval (a) (1,\ oo) (b) (-1,\ oo) (c) (-oo,\ oo) (d) (0,\ oo)

The interval of increase of the function f(x)=x-e^x+tan(2pi//7) is (a) (0,\ oo) (b) (-oo,\ 0) (c) (1,\ oo) (d) (-oo,\ 1)

The function f(x)=x^9+3x^7+64 is increasing on (a) R (b) (-oo,\ 0) (c) (0,\ oo) (d) R_0

The function f(x)=cot^(-1)x+x increases in the interval (a)(1,oo)(b)(-1,oo)(c)(-oo,oo)(d)(0,oo)

The interval in which the function f given by f(x) = x^2 e^(-x) is strictly increasing is (a) ( -oo , oo ) (b) ( -oo , 0 ) (c) ( 2 , oo ) (d) ( 0 , 2 )

The interval of increase of the function f(x)=x-e^(x)+tan(2 pi/7) is (a) (0,oo)(b)(-oo,0)(c)(1,oo)(d)(-oo,1)

If f(x)={x^3,if x^2 =1 then f(x) is differentiable at (a) (-oo,oo)-{1} (b) (-oo,oo)-{1,-1} (c) (-oo,oo)-{1,-1,0} (d) (-oo,oo)-{-1}