Functions in differential calculus

In summary, the conversation is about a student seeking help with a math problem involving a function f(x,y)= 3x^2 + 7y^2. They share a link to the question and explain their attempt at solving it, but their answer was marked incorrect. They ask for clarification and an example related to the problem, and eventually figure out the correct solution on their own. The conversation ends with the student gaining confidence in their abilities.
  • #1
swimmergrl85
2
0

Homework Statement


Here's the link (I scanned my homework), since it's hard to type the entire question on here, considering the mathematics-related symbols. I just want to make sure you all understand what I am asking.

http://i1056.photobucket.com/albums/...ash5dash55.png




Homework Equations


f(x,y)= 3x^2 + 7y^2



The Attempt at a Solution


What I did was derive the function f(x,y)= 3x^2 + 7y^2, which resulted in the answer E_1= 6 delta x, E_2= 14 delta y. However, the answer was declared wrong. I do not know what I did wrong. Was I supposed to derive the function? Could you please help explain this to me? Could you give me an example related to this problem? Please do what you are allowed to do to help me. I understand the need to figure things out for myself.

Thank you so much!
 
Last edited by a moderator:
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  • #2
swimmergrl85 said:

Homework Statement


Here's the link (I scanned my homework), since it's hard to type the entire question on here, considering the mathematics-related symbols. I just want to make sure you all understand what I am asking.

http://i1056.photobucket.com/albums/...ash5dash55.png




Homework Equations


f(x,y)= 3x^2 + 7y^2



The Attempt at a Solution


What I did was derive the function f(x,y)= 3x^2 + 7y^2, which resulted in the answer E_1= 6 delta x, E_2= 14 delta y. However, the answer was declared wrong. I do not know what I did wrong. Was I supposed to derive the function? Could you please help explain this to me? Could you give me an example related to this problem? Please do what you are allowed to do to help me. I understand the need to figure things out for myself.

Thank you so much!

Your link returns "file not found".

RGV
 
Last edited by a moderator:
  • #3
Here is the link. http://i1056.photobucket.com/albums/t377/swimmergrl85/Mathematics/cal3dash5dash55.png

I don't know how the link got screwed up before.

I figured it out. It was obvious after I did 3 delta x^2 + 7 delta y^2, E_1= delta x and E_2= delta y. I divided the 3 delta x^2 +7 delta y^2 by the E_1 and E_2 values, and got 3 delta x for E_1, and 7 delta y for E_2. I use a homework program where I submit my answer, and it tells me if I am right or not, and I was right. I need to believe in myself more.

Thanks for your reply though.
 
Last edited by a moderator:

1. What is a function in differential calculus?

A function in differential calculus is a mathematical relationship between two variables, where one variable is dependent on the other. It describes how a change in the independent variable affects the dependent variable.

2. How is a function represented in differential calculus?

A function in differential calculus is typically represented by an equation, such as f(x) = 3x + 2. This equation shows the relationship between the independent variable, x, and the dependent variable, f(x).

3. What is the derivative of a function?

The derivative of a function in differential calculus represents the rate of change of the function at a specific point. It is the slope of the tangent line to the function at that point and can be used to determine the instantaneous rate of change.

4. How is the derivative of a function calculated?

The derivative of a function is calculated using the rules of differentiation, which involve finding the limit of the change in the function as the change in the independent variable approaches zero. There are various methods for finding derivatives, such as the power rule, product rule, and chain rule.

5. What is the practical application of functions in differential calculus?

Functions in differential calculus have many practical applications, such as determining the velocity and acceleration of moving objects, finding the maximum and minimum values of a function, and analyzing the behavior of complex systems. They are also used extensively in fields such as physics, engineering, and economics.

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