code: def rsqrt(x):
      x = convert_to_tensor(x)
      return torch.rsqrt(x)
  
imports: import math
  import torch
  from keras.backend import standardize_dtype
  from keras.backend.torch.core import convert_to_tensor
  from keras.backend.torch.core import get_device
  from keras.backend.torch.numpy import pad
label_desc: Use image node_id 16 for calling a global function with example usage: rsqrt(x) and returns: torch