Convert rectangular coordinates to polar coordinates: $(\sqrt{2},-\sqrt{2})$

Step 1 ：Given the rectangular coordinates are \((\sqrt{2}, -\sqrt{2})\).

Step 2 ：To convert rectangular coordinates to polar coordinates, we use the following formulas: \[r = \sqrt{x^2 + y^2}\] and \[\theta = \arctan(\frac{y}{x})\].

Step 3 ：Substitute \(x = \sqrt{2}\) and \(y = -\sqrt{2}\) into the formulas, we get \(r = 2.0\) and \(\theta = -0.7853981633974483\) in radians.

Step 4 ：However, it's more common to express the angle in degrees in the context of polar coordinates. So, let's convert the angle from radians to degrees. We get \(\theta = -45.0\) degrees.

Step 5 ：Final Answer: The polar coordinates are \((2, -45^\circ)\). In other words, \(\boxed{(2, -45)}\).