title: How can I plot this sum with sympy plot or matplotlib?
body: <p>Hello I started to work with sympy. <strong>So I got this function and my question is how can I plot this sum. I tried it with sp.plot and plt.plot, but it doesn't work. I just want a coordinate system. I always get Errors like</strong> <em>The same variable should be used in all univariate expressions being plotted.</em> Probably it is a very easy task, but how I said I just started with sympy and don't know how to go on.
  Thanks for all answers!</p>
  <pre><code>import sympy as sp
  import matplotlib.pyplot as plt
  
  k = sp.symbols(&quot;k&quot;)
  n = sp.symbols(&quot;n&quot;)
  a = sp.Sum(((-1)**k)*(x**(2*k+1))/sp.factorial(((2*k+1))), (k, 0, n))
  </code></pre>