What does this symbol mean (partial derivatives)

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Homework Help Overview

The discussion revolves around the concept of partial derivatives in the context of a function g(x,y) defined as g(x,y) = x^3 - 3x^2 + 5xy - 7y^2. The original poster is attempting to verify that the gradient ∇g(0,0) equals zero.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • The original poster calculates the gradient ∇g and questions how to evaluate it at the point (0,0). Some participants clarify that this involves substituting x and y into the gradient expression.

Discussion Status

The discussion is focused on understanding the evaluation of the gradient at a specific point. Guidance has been provided regarding the substitution process, and there is an acknowledgment of the expected outcome being a vector.

Contextual Notes

Participants are navigating the interpretation of the notation ∇g(0,0) and the implications of the result being a vector. There is an emphasis on ensuring clarity in the evaluation process without reaching a definitive conclusion.

Firepanda
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Question : g(x,y) = x^3 - 3x^2 + 5xy - 7y^2

Verify that ∇g(0,0) = 0

I looked on wiki and it said the vector of partial derivatives, so my g(x,y) would become

∇g = (3x^2 - 6x + 5y, 5x -14y)

so what do i do from here? i don't see what its asking, do i plug x and y as 0 and show I get 0? Where do i plug them into?
 
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Firepanda said:
so what do i do from here? i don't see what its asking, do i plug x and y as 0 and show I get 0? Where do i plug them into?
You plug them into the expression for ∇g. That's what ∇g(0,0) mean. What would you get then? Note that your final answer is a vector.
 
Defennder said:
You plug them into the expression for ∇g. That's what ∇g(0,0) mean. What would you get then? Note that your final answer is a vector.

so just a zero vector?
 
Yes, that's what you should get as the question said.
 

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