You can type  the Greek letters at any time into an equation box by typing the appropriate Alt+key combination. This means to hold down the Alt key near the spacebar like a shift key while you type some other character. To learn the keyboard shortcuts:

When your cursor is in an equation box,  click the toolbar button showing Ss. You will see a palette of Greek letters.
    - Hold the mouse briefly over a letter to learn the keyboard shortcut for that Greek symbol.
    - You can also click the appropriate symbol on the palette to insert it into your equation.

The most useful keyboard shortcut to remember is:
 
    Alt + q  = q  (theta)

A few others are

    Alt + m = m  (mu)
    Alt + j =  j  (phi)
    Alt + a = a (alpha)

In the event either of these methods don't work properly for you, as a last resort you can code Greek characters by typing a dollar sign followed by a letter. ANDES will interpret this two-character sequence to mean the Greek symbol that would be entered by the Alt-letter shortcut. For example, if you type v_x = v * cos($qx), Andes will interpret the argument to be qx. However, you won't see the Greek letter displayed on the screen in this case.