Why should I trust that, it's the slope of that point by taking limit?
For the function f(x) = x² for the point 3, i get 6+ h (h is distance)..... Here i have to take limit h->0 to find the slope at that point. What my doubt is, we don't know the second point with which we gonna take the slope from. We assume that as from both sides it approaches 6. But if we try to get closest point, it will go infinitely. Then how can we trust that 6 is the slope at that point, as its impossible to get that most nearest point.