Polar Coordinates Homework: Understanding Second Equation

[rsaad]

Homework Statement

In the attachment, I do not understand how we got the second equation in terms of polar coordinates.

Homework Equations

The Attempt at a Solution

I tried doing it by writing z_dot = (...)z and then plugging in r* exp i theta, but to no avail.

 

[Dick]

Homework Statement

In the attachment, I do not understand how we got the second equation in terms of polar coordinates.

Homework Equations

The Attempt at a Solution

I tried doing it by writing z_dot = (...)z and then plugging in r* exp i theta, but to no avail.

Show how you tried it. z'=r'e^(iθ)+iθ're^(iθ). Try going straight from the "complex notation" to the "polar notation". Divide both sides by e^(iθ) and equate real and imaginary parts.