GNU Emacs Calc 2.02 Manual

7.4.2: Polar Mode

The Calculator normally ``prefers'' rectangular complex numbers in the sense that rectangular form is used when the proper form can not be decided from the input. This might happen by multiplying a rectangular number by a polar one, by taking the square root of a negative real number, or by entering ( 2 SPC 3 ).

The m p (calc-polar-mode) command toggles complex-number preference between rectangular and polar forms. In polar mode, all of the above example situations would produce polar complex numbers.