Approximation by Certain Linear Positive Operators of Two Variables

Figure 2

The convergence of 𝐿_𝑛,𝑚(𝑓;𝑥,𝑦) and 𝑆_𝑛,𝑚(𝑓,𝑥,𝑦) to 𝑓(𝑥,𝑦) for 𝑛,𝑚=30.