Let f : R → R , x ↦ f ( x ) {\displaystyle {}f\colon \mathbb {R} \rightarrow \mathbb {R} ,x\mapsto f(x)} , be a continuous function and let F ( x ) {\displaystyle {}F(x)} be a primitive function for f ( x ) {\displaystyle {}f(x)} . Show that F ( x ) + c x {\displaystyle {}F(x)+cx} is a primitive function for f ( x ) + c {\displaystyle {}f(x)+c} .
