If limx→3f(x)=7\lim_{x \to 3} f(x) = 7limx→3f(x)=7, which conclusion is valid?
f(3)=7f(3) = 7f(3)=7
fff is continuous at x=3x=3x=3
f(x)f(x)f(x) gets close to 777 as xxx gets close to 333
fff is differentiable at x=3x=3x=3