If `f(x)` is differentiable everywhere, then which one of the following is correct?

Let f:R to R be a function such that f(x+y)=f(x)+f(y)"for all", x,y in R If f(x) is differentiable at x=0. then, which one of the following is incorrect?

If f(x) = e^(absx) , then which one of the following is correct ?

If f(x)=|x|+|x-1| , then which one of the following is correct?

If f(x)=|x|+|x-1| , then which one of the following is correct?

For a point of inflection of y= f(X) which one of the following is correct ?

If f:R rarr R be defined as f(x)=sin(|x|) then which one of the following is correct?

Consider the following function f:RtoR such that f(x)=x" if "xge0andf(x)=-x^(2)" if "xlt0 . Then, which one of the following is correct?