code: def _smallest_positive_root(a, b, c):
      """Returns the smallest positive root of a quadratic equation."""
  
      determinant = tf.sqrt(b**2 - 4 * a * c)
  
      # CenterNet implementation. The commented lines implement the fixed version
      # in https://github.com/princeton-vl/CornerNet. Change the implementation
      # after verifying it has no negative impact.
      # root1 = (-b - determinant) / (2 * a)
      # root2 = (-b + determinant) / (2 * a)
  
      # return tf.where(tf.less(root1, 0), root2, root1)
  
      return (-b + determinant) / 2.0
  
file_path: graphics/tensorflow_graphics/projects/points_to_3Dobjects/transforms/targets.py
imports: import tensorflow
  from google3.third_party.tensorflow_models.object_detection.core import box_list
  from google3.third_party.tensorflow_models.object_detection.core import box_list_ops
label_desc: Use image node_id 1 for calling a global function with example usage: _smallest_positive_root(a, b, c) and returns: unknown