In a triangle, we use terms like adjacent and opposite. These refer to sides in relation to angles. In our musical triangle, the drummer is at one angle in the back. This side, where the audience is, is called the opposite side.
Trunc is database function, try using round for numeric values, or change the Processing of Query to database.
Trig Functions: The Functions. The functions are usually abbreviated: sine (sin), cosine (cos), tangent (tan) cosecant (csc), secant (sec), and cotangent (cot). It is often simpler to memorize the the trig functions in terms of only sine and cosine: The functions are usually abbreviated: arcsine (arcsin) arccosine (arccos)