Approximation by Certain Linear Positive Operators of Two Variables

Figure 1

The convergence of 𝐿_𝑛,𝑚(𝑓;𝑥,𝑦) to 𝑓(𝑥,𝑦) for 𝑛,𝑚=5 and 𝑛,𝑚=50.