124 Section 11: Calculating With Complex Numbers

Stack Lift in Complex Mode

Stack lift operates on the imaginary stack as it does on the real stack (the real stack behaves identically in and out of Complex mode). The same functions that enable, disable, or are neutral to lifting of the real stack will enable, disable, or be neutral to lifting of the imaginary stack. (These processes are explained in detail in section 3 and appendix B.)

In addition, every nonneutral function, except and ` causes the clearing of the imaginary X-register when the next number is entered. That is, these functions cause a zero to be placed in the imaginary X-registerwhen the next number is keyed in or recalled. Refer to the stack diagrams above for illustrations. This feature allows you to execute calculator operations using the same key sequences you use outside of Complex mode.*

Manipulating the Real and Imaginary Stacks

}(real exchange imaginary). Pressing ´ } will exchange the contents of the real and imaginary X-registers, thereby converting the imaginary part of the number into the real part and vice-versa. The Y-, Z-, and T-registers are not affected. Press ´ }twice restore a number to its original form.

}also activates Complex mode if it is not already activated.

Temporary Display of the Imaginary X-Register. Press ´ % to momentarily display the imaginary part of the number in the X-registerwithout actually switching the real and imaginary parts. Hold the key down to maintain the display.

Changing Signs

In Complex mode, the function affects only the number in the real X- register – the imaginary X-register does not change. This enables you to change the sign of the real or imaginary part without affecting the other. To key in a negative real or imaginary part, change the sign of that part as you enter it.

If you want to find the additive inverse of a complex number already in the X-register,however, you cannot simply press as you would outside

*Except for the :and ;functions, as explained in this section (page 133).