What Does the Third Derivative Mean?

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In summary, the third derivative is important for physics and engineering because it can help reduce the number of unknowns in an equation.
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  • #2
It's the rate of change of the slope of the first graph.
 
  • #3
Or for example when we want to find a functions maxima or minima, or to determine the convexity of a function. FOr example if f'=f''=0 then if f''' is different from zero the function has a minima of maxima depending on the sign of the f'''.
 
  • #4
Here's a neat example. Suppose when driving a car, the car's acceleration is proportional to the position of your foot on the pedal. Now if your foot is moving with some velocity, then the third derivative of the car's motion is proportional to the velocity of your foot. And if your foot is moving with some acceleration the then the 4th derivative of the car's motion is proportional to the acceleration of your foot.

The third derivative (the jerk) has some other important implications in physics and engineering.
http://en.wikipedia.org/wiki/Jerk
 
  • #5
It's the third derivative of a function.
That's its "meaning".

In some approximative schemes of differential equations, it can be advantageous to express one of the unkown functions in terms of the derivatives of another unkown, thereby reducing the number of unkown functions to be found by increasing the order of the resulting diff.eq(s).
Thereby, third-and higher order derivatives may enter in the diff.eq, even if it starts out like at most a second-order problem like Newton's F=ma


The Boussinesq equation types in fluid mechanics are examples of that.
 
  • #6
Could anyone tell me more detail about third derivative of distance and of others? What does it use for? What about fourth derivative, 5th...?
And my 2nd question is: a mouvement of a object notice by this system equation: x(t)=vxt+x0, y(t)=vy.t+y0, z(t)=vz.t+z0. What is the equation of trajectory, f(x,y,z)=?
Thanks in advance for any reply!

Chhun...
 

FAQ: What Does the Third Derivative Mean?

What is the third derivative?

The third derivative is a mathematical concept that describes the rate of change of the second derivative. It measures how quickly the rate of change is changing.

Why is the third derivative important?

The third derivative is important because it allows us to analyze the curvature and behavior of a function at a specific point. It can also provide information about the concavity and inflection points of a curve.

How is the third derivative calculated?

The third derivative is calculated by taking the derivative of the second derivative. This can be done using the chain rule and product rule, if necessary.

What does a positive third derivative mean?

A positive third derivative means that the rate of change of the second derivative is increasing. This can indicate that the function is becoming more concave up or that the curvature is increasing.

What does a negative third derivative mean?

A negative third derivative means that the rate of change of the second derivative is decreasing. This can indicate that the function is becoming more concave down or that the curvature is decreasing.

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