What Is the Correct Partial Derivative of 6xyz?

In summary, the partial derivative of x3 + y3 + z3 + 6xyz with respect to x is 3x2 + 3z2(∂z/∂x) + 6xy(∂z/∂x) = 0. However, there may be a mistake in the solution guide as the partial derivative of 6xyz should be 6yz if z is independent of x, and 6yz + 6x(∂z/∂x) if z is dependent on x.
  • #1
Calpalned
297
6

Homework Statement


Find (∂z/∂x) of 6xyz

Homework Equations


N/a

The Attempt at a Solution


The correct answer is 6xy(∂z/∂x) but I would like proof of it. I got something different when I tried taking the partial derivative.

6xyz = 6x(yz) = Multiplication rule for derivatives

6(∂x/∂x) + y(∂z/∂x)

What did I do wrong? Thanks
 
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  • #2
Calpalned said:

Homework Statement


Find (∂z/∂x) of 6xyz
Is this the complete problem statement? Generally speaking you don't find "∂z/∂x" of something, and more than you find "dy/dx" of something. You can, however, find the derivative with respect to, say, x of a function (denoted d/dx(f)) or the partial of some function with respect to, say z (denoted ∂/∂x(f).

The symbols ∂z/∂x and dy/dx represent derivatives, whereas the symbols ∂/∂x and d/dx represent operators that can be applied to functions.

Please verify that what you're providing is the complete problem statement.
Calpalned said:

Homework Equations


N/a

The Attempt at a Solution


The correct answer is 6xy(∂z/∂x) but I would like proof of it. I got something different when I tried taking the partial derivative.

6xyz = 6x(yz) = Multiplication rule for derivatives

6(∂x/∂x) + y(∂z/∂x)

What did I do wrong? Thanks
 
  • #3
The full question is find (∂z/∂x) of x3 + y3 + z3 + 6xyz = 1
My textbook says the partial derivative is 3x2 + 3z2(∂z/∂x) + 6xy(∂z/∂x) = 0
I don't get how to take the derivative of the red part.
 
  • #4
Calpalned said:
The full question is find (∂z/∂x) of x3 + y3 + z3 + 6xyz = 1
My textbook says the partial derivative is 3x2 + 3z2(∂z/∂x) + 6xy(∂z/∂x) = 0
I don't get how to take the derivative of the red part.
The derivative above is from my textbook's solutions guide.
 
  • #5
Calpalned said:
The full question is find (∂z/∂x) of x3 + y3 + z3 + 6xyz = 1
My textbook says the partial derivative is 3x2 + 3z2(∂z/∂x) + 6xy(∂z/∂x) = 0
I don't get how to take the derivative of the red part.
Corrected to: find (∂z/∂x) of if x3 + y3 + z3 + 6xyz = 1

It looks to me like there's a mistake in the solution guide.
##∂/∂x(x^3) = 3x^2## and ##∂/∂x(y^3) = 0## and ##∂/∂x(z^3) = 3z^2 ∂z/∂x##

BUT
##∂/∂x(6xyz) = 6yz## if z is independent of x, in which case ∂z/∂x would be 0. However, if z is dependent on x, you need to use the product rule. Since you're asked to find ∂z/∂x, it must be the case that z is a function of x (is dependent on x).
 

FAQ: What Is the Correct Partial Derivative of 6xyz?

1. What is an implicit partial derivative?

An implicit partial derivative is a mathematical concept that describes the rate of change of a function with respect to one of its independent variables, while holding all other independent variables constant. It is used when a function is expressed implicitly, rather than explicitly, as a function of its independent variables.

2. How is an implicit partial derivative different from an explicit partial derivative?

An explicit partial derivative is calculated by directly differentiating a function with respect to one of its independent variables. In contrast, an implicit partial derivative involves differentiating an equation that relates multiple variables, and therefore requires the use of implicit differentiation.

3. Why are implicit partial derivatives important?

Implicit partial derivatives are important because they allow us to analyze the behavior of functions that are expressed implicitly, which is often the case in real-world applications. They also help us to understand the relationships between different variables in a function.

4. How do you calculate an implicit partial derivative?

To calculate an implicit partial derivative, you must use the chain rule to differentiate each term in the equation with respect to the variable of interest. The resulting expression will include both the partial derivative of the function and the derivative of the variable with respect to which it is being differentiated.

5. In what fields are implicit partial derivatives commonly used?

Implicit partial derivatives are commonly used in fields such as physics, engineering, economics, and statistics, where functions are often expressed implicitly. They are also important in optimization and modeling processes, as they allow us to analyze the behavior of complex systems with multiple variables.

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