code: def _exp_factor_dct3(x, n, axis, dtype, norm_factor):
      """Twiddle & scaling factors for computation of DCT/DST-III via FFT."""
      tmp = cupy.empty((n,), dtype=dtype)
      _mult_factor_dct3(tmp.real, n, norm_factor, tmp)
      if x.ndim == 1:
          return tmp
      # prepare shape for broadcasting along non-transformed axes
      tmp_shape = [1] * x.ndim
      tmp_shape[axis] = n
      tmp_shape = tuple(tmp_shape)
      return tmp.reshape(tmp_shape)
  
imports: import math
  import numbers
  import operator
  import numpy
  import cupy
  from cupy import _core
  from cupy.fft._fft import _cook_shape
  from cupyx.scipy.fft import _fft
label_desc: Use image node_id 7 for calling a global function with example usage: _exp_factor_dct3(x, n, axis, dtype, norm_factor) and returns: tmp, tmp