Engineering Procedure From an unknown but astute source:    "Every new engineer must learn early that it is never good taste to designate the sum of two quantities in the form: 1 + 1 = 2 (1) "Anyone who has made a study of advanced mathematics is aware that: 1 = ln e and that: 1 = sin2x+ cos2x further: "Therefore, Eq. (1) can be expressed more scientifically as: "This may be further simplified by use of the relations: and "Equation (2) may therefore be rewritten: "At this point, it should be abvious that Eq. (3) is much clearer and more easily understood than Eq. (1). Other methods of a similar nature could be used to clarify Eq. (1) but these are easily discovered once the reader grasps the underlying principles."