# What are the conditions of a function to be differentiable?

## What are the conditions of a function to be differentiable?

A function f is differentiable at x=a whenever f′(a) exists, which means that f has a tangent line at (a,f(a)) and thus f is locally linear at the value x=a. Informally, this means that the function looks like a line when viewed up close at (a,f(a)) and that there is not a corner point or cusp at (a,f(a)).

### What is sufficient condition of differentiability?

A sufficient condition for the existence of f. ′(z0) comes from Multivariable Calculus: if u(x, y) has first partial derivatives, then it is differentiable at every point where those partial derivatives are continuous.

#### Under what conditions is a function not 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.

**How do you prove differentiability?**

A differentiable function is a function that can be approximated locally by a linear function. [f(c + h) − f(c) h ] = f (c). The domain of f is the set of points c ∈ (a, b) for which this limit exists. If the limit exists for every c ∈ (a, b) then we say that f is differentiable on (a, b).

**How do you show differentiability?**

To show that f is differentiable at all x∈R, we must show that f′(x) exists at all x∈R. Recall that f is differentiable at x if limh→0f(x+h)−f(x)h exists. And so we see that f is differentiable at all x∈R with derivative f′(x)=−5.

## What are the conditions for function?

A Condition for a Function: Set A and Set B should be non-empty. In a function, a particular input is given to get a particular output. So, A function f: A->B denotes that f is a function from A to B, where A is a domain and B is a co-domain.

### When can a function be differentiated?

Apply the power rule to differentiate a function. The power rule states that if f(x) = x^n or x raised to the power n, then f'(x) = nx^(n – 1) or x raised to the power (n – 1) and multiplied by n. For example, if f(x) = 5x, then f'(x) = 5x^(1 – 1) = 5.

#### Is continuity necessary for differentiability?

Continuity is required for differentiability.

**Is differentiable continuous?**

If a function is differentiable then it’s also continuous. This property is very useful when working with functions, because if we know that a function is differentiable, we immediately know that it’s also continuous.

**Can discontinuous function be differentiable?**

If a function is discontinuous, automatically, it’s not differentiable.

## What condition is the correct one for good differentiation?

In order to achieve good differentiation, the following two conditions should be satisfied: The time constant RC of the circuit should be much smaller than the time period of the input wave. The value of XC should be 10 or more times larger than R at the operating frequency.

### What are the three conditions for continuity?

For a function to be continuous at a point, it must be defined at that point, its limit must exist at the point, and the value of the function at that point must equal the value of the limit at that point.

#### How to prove that the function is not differentiable?

If a graph has a sharp corner at a point,then the function is not differentiable at that point.

**How to check differentiability of a function at a point?**

All polynomial,exponential,trigonometric,logarithmic,rational functions are differentiable in their domain.

**When are functions not differentiable?**

Rational functions are not differentiable. They are undefined when their denominator is zero, so they can’t be differentiable there. For example, we can’t find the derivative of f ( x) = 1 x + 1 at x = − 1 because the function is undefined there. Functions that wobble around all over the place like sin ( 1 x) are not differentiable.

## What is the difference between continuous and differentiable?

– Cusp or Corner (sharp turn) – Discontinuity (jump, point, or infinite) – Vertical Tangent (undefined slope)