Present work contains a method to obtain Jackson and Stechkin type inequalities of approximation by integral functions finite degree (IFFD) in some variable exponent Lebesgue space real defined on $\boldsymbol{R}:=\left( -\infty ,+\infty \right) $. To do this, we employ transference theorem which produce norm starting from $\mathcal{C}(\boldsymbol{R})$, the class bounded uniformly continuous $\...