#### ElijahRockers

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**1. The problem statement, all variables and given/known data**

For the transformation, draw the lattice lines, calculate the derivative, and calculate the Jacobian.

[itex]x=rcos\theta[/itex]

[itex]y=rsin\theta[/itex]

**3. The attempt at a solution**

I drew the lattice lines correctly. What I am confused about is the derivative. Since x and y are both functions of r and theta, what derivative are they talking about? Wouldn't I have to take the partial with respect to R or theta? This section is supposed to be on calculating determinants.

I understand that the Jacobian is the determinant of a particular matrix, but where does this matrix come from?