Update app.py

app.py

@@ -178,6 +178,10 @@ NOTE: For eigenvalue problems, use 'lam = Symbol('lam')' instead of importing fr
 
    8. If calculating integrals, write the SymPy code to compute the original integral directly with respect to the original variable of integration,
       not any integral that might have been rewritten with a variable substitution.
+
+   9. If using SymPy to evalute an infinite sum, attempt using the infinite sum, and in addition report what the sum of the first 100 terms is as a sanity check.
+
+   10. Do not use SciPy.
       
 ```python
 from sympy import Matrix, symbols, solve