code: def U2(phi, delta):
      r"""Return the matrix representation of the U2 gate.
  
      .. math::
  
          U_2(\phi, \delta) = \frac{1}{\sqrt{2}}\begin{bmatrix} 1 & -\exp(i \delta)
          \\ \exp(i \phi) & \exp(i (\phi + \delta)) \end{bmatrix}
  
      Args:dd
          phi (float): azimuthal angle :math:`\phi`
          delta (float): quantum phase :math:`\delta`
      """
      return (
          1
          / math.sqrt(2)
          * math.array(
              [
                  [1.0, -math.exp(delta * 1j)],
                  [math.exp(phi * 1j), math.exp((phi + delta) * 1j)],
              ]
          )
      )
  
imports: import pennylane
  from pennylane import numpy
  from pennylane import math
label_desc: Use image node_id 7 for calling a global function with example usage: U2(phi, delta) and returns: unknown