functions

A superadditive function $f(\cdot)$ satisfies the following property $$ f\left(x_1+x_2\right) \geq f\left(x_1\right)+f\left(x_2\right) $$ Which of the following functions is a supe...

Consider the following statements about the linear dependence of the real valued functions $${y_1} = 1,\,\,{y_2} = x$$ and $${y_3} = {x^2}$$. Over the field of real numbers. $${\rm...

If x>y>1, which of the following must be true? $$$\begin{array}{l}\mathrm i.\;\ln\left(\mathrm x\right)>\ln\left(\mathrm y\right)\;\;\;\;\;\;\;\;\;\;\mathrm{ii}.\;\;\mathrm e^\math...

Given that f(y) = |y| / y, and q is any non-zero real number, the value of | f(q) - f(-q) | is