Determine whether or not F is a conservative vector field. If it is, find a function f such that F = ∇f. (If the vector field is not conservative, enter DNE.) F(x, y) = (2x − 6y) i + (−6x + 6y − 7) j

Respuesta :

We're looking for a scalar function [tex]f(x,y)[/tex] such that [tex]\nabla f(x,y)=\vec F(x,y)[/tex]. That is,

[tex]\dfrac{\partial f}{\partial x}=2x-6y[/tex]

[tex]\dfrac{\partial f}{\partial y}=-6x+6y-7[/tex]

Integrate the first equation with respect to [tex]x[/tex]:

[tex]f(x,y)=x^2-6xy+g(y)[/tex]

Differentiate with respect to [tex]y[/tex]:

[tex]-6x+6y-7=-6x+\dfrac{\mathrm dg}{\mathrm dy}\implies\dfrac{\mathrm dg}{\mathrm dy}=6y-7[/tex]

Integrate with respect to [tex]y[/tex]:

[tex]g(y)=3y^2-7y+C[/tex]

So [tex]\vec F[/tex] is indeed conservative with the scalar potential function

[tex]f(x,y)=x^2-6xy+3y^2-7y+C[/tex]

where [tex]C[/tex] is an arbitrary constant.

As there exists a Scalar Function f(x,y) whose gradient is a function F(x,y) so the given F(x,y) is a  conservative vector field.

The Scalar function f(x,y) is given as follows

[tex]f(x,y) = x^2 -6xy +3y^2 -7y +C \\where\; C \;is \; an\; arbitary \; constant[/tex]

Given,   Gradient of f(x,y) = F(x, y) = ∇f (x,y) =  (2x − 6y) i + (−6x + 6y − 7) j

We need a scalar function  f (x,y ) such that

[tex]\partial f/\partial x = 2x-6y \....(1) \\\\\\partial f/\partial y = (-6x + 6y- 7) .....(2) \\\\[/tex]

Equation (1) and Equation (2) hold true  (Given)

Integrate the first equation with respect to x  we get

[tex]f = x^2 -6xy +g(y)[/tex]....(3)

On differentiating equation (3)  with respect to y

[tex]\partial f /\partial y = -6x +\partial g\//\partial y[/tex]  ....(4)

from solving Equation (2) and Equation (4 ) we get

[tex]\partial g /\partial y = 6y-7[/tex]

Integrate Equation (4) with respect to  y

[tex]g(y) = 3y^2 -7y[/tex] + C

putting this value of g(y) in Equation (3) we get

[tex]f(x,y) = x^2 -6xy +3y^2 -7y +C \\where\; C \;is \; an\; arbitary \; constant[/tex]

For more information please refer to  the link below

https://brainly.com/question/13020257

So  is indeed conservative with the scalar potential function

where  is an arbitrary constant.