trigonometry ratio

Trigonometric Ratios

"Trigon" is greek for triangle, and "metric" is greek for measurement. The trigonometric ratios are special measurements of a right triangle (a triangle with one angle measuring 90^o). Remember that the two sides of a right triangle which form the right angle are called the legs, and the third side (opposite the right angle) is called thehypotenuse. adding article

      

relation and function

Relation:  A relation is simply a set of ordered pairs.

  The first elements in the ordered pairs (the x-values), form the domain.  The second elements in the ordered pairs (the y-values), form the range.  Only the elements "used" by the relation constitute the range. adding article