Hard Partial Derivatives question

In summary, we are asked to find the partial derivatives of ∂z/∂θ and ∂z/∂ф in terms of x and t for the function z = cos(kx-ωt), where θ=t2-x and ф = x2+t. Using the chain rule for partial differentiation, we can express these derivatives as shown above.
  • #1
steve0606
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0

Homework Statement


Taking k and ω to be constant, ∂z/∂θ and ∂z/∂ф in terms of x and t for the following function
z = cos(kx-ωt), where θ=t2-x and ф = x2+t.


Homework Equations





The Attempt at a Solution


I'm finding this difficult as t and x are not stated explicitly. I know how to do the chain rule with partial differentiation.
 
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  • #2
Then where did you get this problem? The chain rule for more than one variable is given in any Calculus text.

[tex]\frac{\partial f}{\partial \theta}= \frac{\partial f}{\partial x}\frac{\partial x}{\partial \theta}+ \frac{\partial f}{\partial t}\frac{\partial t}{\partial \theta}[/tex]

[tex]\frac{\partial f}{\partial \phi}= \frac{\partial f}{\partial x}\frac{\partial x}{\partial \phi}+ \frac{\partial f}{\partial t}\frac{\partial t}{\partial \phi}[/tex]
 

Related to Hard Partial Derivatives question

1. What is a hard partial derivatives question?

A hard partial derivatives question is a mathematical problem that involves finding the partial derivatives of a multivariable function. These derivatives are calculated with respect to one or more variables while holding all other variables constant.

2. Why are partial derivatives useful?

Partial derivatives are useful because they allow us to analyze how a multivariable function changes with respect to each individual variable. This information is important in many areas of science, including physics, engineering, and economics.

3. How do you solve a hard partial derivatives question?

To solve a hard partial derivatives question, you will need to use the chain rule and the product rule, as well as other derivative rules. You will also need to understand how to take derivatives of different types of functions, such as polynomials, exponential functions, and trigonometric functions.

4. What are some real-world applications of partial derivatives?

Partial derivatives have many real-world applications, including optimization problems in economics and engineering, analyzing the rate of change in physical systems, and determining the sensitivity of a system to input variables.

5. Are there any common mistakes when solving hard partial derivatives questions?

Yes, some common mistakes when solving hard partial derivatives questions include forgetting to use the chain rule, mixing up the order of the variables, and making errors in the algebraic simplification of the problem. It is important to carefully check your work and make sure all steps are correct when solving these types of problems.

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