Graph (mapping)/R/Addition and multiplication/Exercise

Sketch the graph of the real addition

$+\colon \mathbb {R} \times \mathbb {R} \longrightarrow \mathbb {R} ,(x,y)\longmapsto x+y,$

and the graph of the real multiplication

$\cdot \colon \mathbb {R} \times \mathbb {R} \longrightarrow \mathbb {R} ,(x,y)\longmapsto x\cdot y.$

Create a solution