## Which functions are derivable?

Polynomials are differentiable for all arguments. A rational function is differentiable except where q(x) = 0, where the function grows to infinity. This happens in two ways, illustrated by . Sines and cosines and exponents are differentiable everywhere but tangents and secants are singular at certain values.

## What is a non differentiable function?

A function that does not have a differential. For example, the function f(x)=|x| is not differentiable at x=0, though it is differentiable at that point from the left and from the right (i.e. it has finite left and right derivatives at that point).

**How do you determine if a function is differentiable?**

A function is formally considered differentiable if its derivative exists at each point in its domain, but what does this mean? It means that a function is differentiable everywhere its derivative is defined. So, as long as you can evaluate the derivative at every point on the curve, the function is differentiable.

### Why is a cusp not differentiable?

In the same way, we can’t find the derivative of a function at a corner or cusp in the graph, because the slope isn’t defined there, since the slope to the left of the point is different than the slope to the right of the point. Therefore, a function isn’t differentiable at a corner, either.

### Do all continuous functions have Antiderivatives?

Indeed, all continuous functions have antiderivatives. But noncontinuous functions don’t. Take, for instance, this function defined by cases.

**Why are polynomials continuous everywhere?**

Every polynomial function is continuous everywhere on (−∞, ∞). Every rational function is continuous everywhere it is defined, i.e., at every point in its domain. Its only discontinuities occur at the zeros of its denominator. Corollary: If p is a polynomial and a is any number, then lim p(x) = p(a).

## How do you know if a function is non-differentiable?

A function is not differentiable at a if its graph has a vertical tangent line at a. The tangent line to the curve becomes steeper as x approaches a until it becomes a vertical line. Since the slope of a vertical line is undefined, the function is not differentiable in this case.

## What function has no derivative?

In mathematics, the Weierstrass function is an example of a real-valued function that is continuous everywhere but differentiable nowhere. It is an example of a fractal curve. It is named after its discoverer Karl Weierstrass.

**Can a limit exist at a cusp?**

At a cusp, the function is still continuous, and so the limit exists. Since g(x) → 0 on both sides, the left limit approaches 1 × 0 = 0, and the right limit approaches −1 × 0 = 0. Since both one-sided limits are equal, the overall limit exists, and has value zero.

### Can a cusp have a derivative?

3. At any sharp points or cusps on f(x) the derivative doesn’t exist. If we look at our graph above, we notice that there are a lot of sharp points. If we look at any point between −3 and −2 and take the tangent line, it will be the exact same as the original line.

### What does derivative do in basis of function?

In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus.

**What are basic derivatives?**

At its most basic, a financial derivative is a contract between two parties that specifies conditions under which payments are made between two parties. Derivatives are “derived” from underlying assets such as stocks, contracts, swaps, or even, as we now know, measurable events such as weather.

## How can I find the derivative?

The first way of calculating the derivative of a function is by simply calculating the limit that is stated above in the definition. If it exists, then you have the derivative, or else you know the function is not differentiable. As a function, we take f (x) = x2.

## What are some examples of derivatives?

A derivative is an instrument whose value is derived from the value of one or more underlying, which can be commodities, precious metals, currency, bonds, stocks, stocks indices, etc. Four most common examples of derivative instruments are Forwards, Futures, Options and Swaps.