Suppose a change of coordinates T:R2→R2 from the uv-plane to the xy-plane is given byx=−4v−3u−1, y=3−4u−5v.(a) Find the absolute value of the determinant of the Jacobian for this change of coordinates.∣∣∣∂(x,y)∂(u,v)∣∣∣=∣∣∣det⎡⎣⎢⎢⎤⎦⎥⎥∣∣∣= (b) If a region D∗ in the uv-plane has area 7.25, find the area of the region T(D∗) in the xy-plane.

Respuesta :

ZUK

Answer:

The answer is 7.25.  That is there will be no change.

Step-by-step explanation:

The equations of differential vector transformation from the v-u plane to the x-y plane is given by,

[tex]\left[\begin{array}{ccc}dx\\dy\end{array}\right] = \left[\begin{array}{ccc}dx/dv&dx/du\\dy/dv&dy/du\end{array}\right] \left[\begin{array}{ccc}dv\\du\end{array}\right][/tex]

where the square matrix given is the Jacobian matrix and we can evaluate it by differentiating the equation for x and y given in the question by v and u and we will obtain the following matrix,

[tex]J = \left[\begin{array}{ccc}-4&-3\\-5&-4\end{array}\right][/tex] .

Differential area transformation from v-u coordinate system to the x-y coordinate systen is given by,

[tex]dxdy = Det(J)dvdu[/tex]

where Det(J), is evaluated as below,

[tex]Det(J) = (-4)*(-4) - (-3)*(-5) = 1[/tex]

which we plug into the above equation to obtain,

[tex]dxdy = dvdu[/tex]

in part b) area of the region D in the u-v plane is given as 7.25 that is dvdu=7.25 , that means according to the above equation that the area of the corresponding transformed region in the x-y plane that is dxdy will also be the same according o the above equation,So,

[tex]Area T(D) = dxdy = dvdu =Area D= 7.25[/tex]

a. The magnitude of the Jacobian is |J(x,y)/(u,v)| = |- 1| = 1

b. The area in region T(D∗) in the xy-plane is 7.25

Since x = -4v - 3u - 1 and y = 3 - 4u - 5v

a. The magnitude of the Jacobian

The magnitude of the Jacobian is |J(x,y)/(u,v)| = |- 1| = 1

The Jacobian J(x,y)/(u,v) = dx/du × dy/dv - dx/dv × dy/du

Since x = -4v - 3u - 1

dx/du = d(-4v - 3u - 1)/du = -3, dx/dv = d(-4v - 3u - 1)/dv = -4

Also, y = 3 - 4u - 5v

dy/du = d(3 - 4u - 5v)/du = - 4 and dy/dv = d(3 - 4u - 5v)/dv = - 5

Substituting these values into the Jacobian, we have

J(x,y)/(u,v) = dx/du × dy/dv - dx/dv × dy/du

J(x,y)/(u,v) = - 3 × - 5  - (-4) × (-4)

J(x,y)/(u,v) = 15  - 16

J(x,y)/(u,v) = - 1

So, the magnitude of the Jacobian is |J(x,y)/(u,v)| = |- 1| = 1

b. Area in the region T(D∗)

The area in region T(D∗) in the xy-plane is 7.25

Since the area in the region D∗ in the uv-plane is A = 7.25,

The area in region T(D∗) in the xy-plane is A' = |J(x,y)/(u,v)|A

A' = 1 × A

A' = A

A' = 7.25

The area in region T(D∗) in the xy-plane is 7.25

Learn more about Jacobian here:

https://brainly.com/question/19427145