Function f is continuous at a point a if the following conditions are satisfied.
- f(a) is defined
- limx→af(x) exists
- limx→af(x) = f(a)
Now → limx→3(x+3)²/(x-3) = k
so using L'hospital rule (differentiating on both sides i.e., denominator and numerator), we get
2(x+3) = k
Now substitute x=3 => k=12