 # Does A Limit Have To Be Differentiable?

## How do you know if a graph is not differentiable?

If there derivative can’t be found, or if it’s undefined, then the function isn’t differentiable there.

So, for example, if the function has an infinitely steep slope at a particular point, and therefore a vertical tangent line there, then the derivative at that point is undefined..

## Can a function be differentiable and not continuous?

When a function is differentiable it is also continuous. But a function can be continuous but not differentiable. For example the absolute value function is actually continuous (though not differentiable) at x=0.

## Can a function be differentiable at a hole?

No. A function with a removable discontinuity at the point is not differentiable at since it’s not continuous at . … Thus, is not differentiable. However, you can take an arbitrary differentiable function .

## How do you know if a function is continuous?

If a function f is only defined over a closed interval [c,d] then we say the function is continuous at c if limit(x->c+, f(x)) = f(c). Similarly, we say the function f is continuous at d if limit(x->d-, f(x))= f(d).

## How do you know if a limit is differentiable?

Lesson 2.6: Differentiability: A function is differentiable at a point if it has a derivative there. … Example 1: … If f(x) is differentiable at x = a, then f(x) is also continuous at x = a. … f(x) − f(a) … (f(x) − f(a)) = lim. … (x − a) · f(x) − f(a) x − a This is okay because x − a �= 0 for limit at a. … (x − a) lim. … f(x) − f(a)More items…

## When can a limit not exist?

Limits typically fail to exist for one of four reasons: The one-sided limits are not equal. The function doesn’t approach a finite value (see Basic Definition of Limit). The function doesn’t approach a particular value (oscillation).

## Can a limit exist at a hole?

The first, which shows that the limit DOES exist, is if the graph has a hole in the line, with a point for that value of x on a different value of y. … If there is a hole in the graph at the value that x is approaching, with no other point for a different value of the function, then the limit does still exist.

## What does it mean when a graph is differentiable?

A function is differentiable at a point when there’s a defined derivative at that point. This means that the slope of the tangent line of the points from the left is approaching the same value as the slope of the tangent of the points from the right.

## What does a non differentiable function look like?

Generally the most common forms of non-differentiable behavior involve a function going to infinity at x, or having a jump or cusp at x. … If the function f has the form , f will usually be singular at argument x if h vanishes there, h(x) = 0.

## What does it mean for a limit to be differentiable?

It is the limit of a rational function, the difference quotient of f(x) at x = a. We say that f(x) is differentiable at x = a if this limit exists. … If f(x) is differentiable at every point in its domain, we say that f(x) is a differentiable function on its domain.

## Is every continuous function integrable?

If f is continuous everywhere in the interval including its endpoints which are finite, then f will be integrable. … A function is continuous at x if its values sufficiently near x are as close as you choose to one another and to its value at x .

## Is a straight line differentiable?

If a function f is differentiable at its entire domain, that simply means that you can zoom into each point, and it will resemble a straight line at each one (though, obviously, it can resemble a different line at each point – the derivative need not be constant). … (For all other x, of course, it is differentiable).

## At what point is the function not differentiable?

We can say that f is not differentiable for any value of x where a tangent cannot ‘exist’ or the tangent exists but is vertical (vertical line has undefined slope, hence undefined derivative). Below are graphs of functions that are not differentiable at x = 0 for various reasons.

## Do you have to be continuous to be differentiable?

In particular, any differentiable function must be continuous at every point in its domain. The converse does not hold: a continuous function need not be differentiable. … Informally, this means that differentiable functions are very atypical among continuous functions.