HP -225 Owner's Manual page 56

Polar/Rectangular Coordinate Conversions
Coordinate conversions use the four coordinate conversion registers.
In general, if you've just keyed in a number, pressing a coordinate
conversion key stores the number in the register. A calculation occurs
when you press one coordinate conversion key right after another.
(x-coordinate, y-coordinate)
Coordinate Conversion Keys and Registers
Keys Register Description:
B (xCOORD] x* Stores the x-coordinate, or calculates the x-co-
ordinatet using the contents of r and 6.
B (»coorD y* Stores the y-coordinate, or calculates the y-co-
ordinate? using the contents of r and 6.
B(rADIUS rr Stores the radius, or calculates the radius' us-
ing the contents of x and y.
B(ANGLE 0 Stores the angle, or calculates the anglet using
the contents of x and y. The value is interpreted
according to the current angular mode—decimal
degrees, radians, or grads.
* These storage locations are separate from the variables X, Y, and R.
T Both coordinates are calculated. For example, calculating x changes the contents of both x
and y; calculating r changes the contents of both r and 6.
48 3: Numeric Functions