title: class sympy.core.add.Add convert to float
body: <p>This part of program on Python uses SymPy library.
  As a result it's produces a value in <strong>sympy.core.add.Add</strong> class which is not capable with other parts of the program.</p>
  
  <pre><code>from sympy import *
  x = symbols('x')
  y = 1 - (0.1 * coeff1) / (x + 2) - sin(x) * (2 * x + coeff1)
  yprime = y.diff(x)
  </code></pre>
  
  <p>How to convert <strong>sympy.core.add.Add</strong> class to ordinary <strong>float</strong> or <strong>int</strong> in order to use variable <strong>yprime</strong> in further calculations?</p>