Derivative of this piecewise function?

In summary, the question is whether the derivative of a piecewise defined function should also be piecewise defined. The response is that the derivative can be written as a normal function, with Dirac delta functions at the points of discontinuity. The graph of the function will provide the answer. The function has no gaps in its definition but has discontinuities, and its derivative has even more discontinuities.
  • #1
Inertigratus
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Homework Statement


I have this piecewise defined function and am wondering if the derivative is supposed to be piecewise defined as well?
Or could I just write it out on a line like a "normal" function?

Homework Equations


x(t) = {-14t : 0[itex]\leq[/itex]|t|< 1, 2sgn(t) : 1[itex]\leq[/itex]|t|< 7, (-12/7)sgn(t) : 7[itex]\leq[/itex]|t|< 14, 0 : 14[itex]\leq[/itex]|t| }

The Attempt at a Solution


I'm thinking I can write the derivative as a normal function. Since the piecewise functions are defined with no time-jumps between them and the derivative will have Dirac delta functions defined at the function incontinuities. Therefor the derivative should be continuous on the interval:
0[itex]\leq[/itex]|t|[itex]\leq[/itex]14.
Is this correct?
 
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  • #2
Graph the function.

That should tell you the answer.

There are no gaps in the function definition -- if you are referring to the fact that the domain of the function is (-∞, ∞). However, this function has discontinuities at several places. Its derivative has even more discontinuities than the function itself !
 
  • #3
Oh right, I asked a little too quick before thinking it through enough.
Thanks!
 

FAQ: Derivative of this piecewise function?

What is a derivative?

A derivative is a mathematical concept that represents the rate of change of a function at a specific point. It measures how much the output of a function changes when the input changes.

How do you find the derivative of a piecewise function?

To find the derivative of a piecewise function, you need to find the derivative of each piece separately and then combine them together using the rules of derivatives. You also need to make sure that the function is continuous at the points where the pieces meet.

What is the difference between a derivative and an antiderivative?

A derivative measures the rate of change of a function, while an antiderivative measures the original function that would produce a given derivative. In other words, a derivative is the slope of a function, while an antiderivative is the function itself.

Why is the derivative of a constant function equal to zero?

The derivative of a constant function is equal to zero because the slope of a constant function is always zero. This means that the function does not change as the input changes, and therefore, its derivative is zero.

What is the relationship between a function and its derivative?

The derivative of a function represents the slope of the function at a specific point. It tells us how much the output of the function changes as the input changes. The derivative can also be used to find the maximum and minimum values of a function and to determine the concavity of a function.

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