Optimal Direction for Mosquito Flight to Warmth

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Homework Help Overview

The problem involves determining the optimal direction for a mosquito to fly towards warmth based on a temperature function defined in three-dimensional space. The temperature at a point (x,y,z) is given by T(x,y,z) = x^2 + y^2 - z, and the mosquito is located at the point (1,1,2).

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of the gradient of the temperature function and its implications for determining the direction of flight. There are questions about the correctness of the unit vector derived from the gradient and whether the initial position of the mosquito is adequately considered.

Discussion Status

The discussion is ongoing, with some participants affirming the initial calculations while others raise concerns about the assumptions made, particularly regarding the unit vector and the relevance of the mosquito's starting position.

Contextual Notes

There is a noted confusion regarding the categorization of the problem within the forum, as it involves concepts typically covered in calculus rather than precalculus. This may affect the framing of the discussion.

abrowaqas
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Homework Statement


The temperature at a point (x,y,z) in space is given by
T(x,y,z) = x^2+y^2-z. a mosquito located at (1,1,2) desires to fly in such a direction that it will get warm as soon as possible. in what direction should it fly?

Homework Equations


Grad T = Txi+Tyj+Tkz


The Attempt at a Solution


i first take its grad T = 2xi+2yj-k

then for direction i just get its unit vector... that is 1/3(2xi+2yj-k) ..

am i right or wrong
 
Physics news on Phys.org
looks ok to me
 
abrowaqas said:

Homework Statement


The temperature at a point (x,y,z) in space is given by
T(x,y,z) = x^2+y^2-z. a mosquito located at (1,1,2) desires to fly in such a direction that it will get warm as soon as possible. in what direction should it fly?

Homework Equations


Grad T = Txi+Tyj+Tkz


The Attempt at a Solution


i first take its grad T = 2xi+2yj-k

then for direction i just get its unit vector... that is 1/3(2xi+2yj-k) ..

am i right or wrong

You didn't use the information that the mosquito starts at (1, 1, 2). Also, why do you think that (1/3)(2xi + 2yj - k) is a unit vector?
 
How did a problem involving the gradient of a vector function get into the "Precalculus Homework" section? I'm going to move this to the "Calculus and beyond" section.

(1/3)(2i+ 2j- k) is a unit vector. Whether or not (1/3)(2xi+ 2yj- k) is depends upon the values of x and y.
 
sorry, looked a little quickly & got the jist of it - all good pick-ups
 

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