Including adequate ALT text allows the screen reader to correctly pronounce the equation.

The ALT text for the above graphic is coded like this: <IMG SRC="algebra.gif" WIDTH="162" HEIGHT="26" ALT="A cubed plus B cubed equals the quantity A plus B times the quantity A squared minus A,B plus B squared.">

The ALT text for the above graphic is coded like this: <IMG SRC="trig.gif" WIDTH="187" HEIGHT="21" ALT="Sine of the quantity A plus B equals the quantity sine A times cosine B plus the quantity cosine A times sine B.">