Update Polynomial Tensor example — use torch.pi instead of math.pi

[sekyondaMeta]

Description

The Tensors (Learning PyTorch with Examples) tutorial contains outdated patterns that should be modernized.

Changes needed

Suboptimal / Outdated Patterns

Issue	Current Code	Modern Alternative	Notes
Using math.pi instead of torch.pi	torch.linspace(-math.pi, math.pi, 2000, ...)	torch.linspace(-torch.pi, torch.pi, 2000, ...)	torch.pi available since PyTorch 1.8.0. Avoids the extra import math.

Files

• beginner_source/examples_tensor/polynomial_tensor.py

[spzala]

/assigntome