I need to define a function that checks if the input function is continuous at a point with sympy.

I searched the sympy documents with the keyword "continuity" and there is no existing function for that. I think maybe I should consider doing it with limits, but I'm not sure how.

```
def check_continuity(f, var, a):
try:
f = sympify(f)
except SympifyError:
return("Invaild input")
else:
x1 = Symbol(var, positive = True)
x2 = Symbol(var, negative = True)
//I don't know what to do after this
```

Yes, you need to use the limits.

The formal definition of continuity at a point has three conditions that must be met. A function

f(x) is continuous at a point wherex=ciflimx —> cf(x) existsf(c) exists (That is,cis in the domain off.)limx —> cf(x) =f(c)SymPy can compute symbolic limits with the limit function.

See: https://docs.sympy.org/latest/tutorial/calculus.html#limits