| Line 1: |
Line 1: |
| − | Trigonometry is the study of angles and [[triangle]]s, relying heavily on three basic functions: [[sine]], [[cosine]] and [[tangent]]. These functions are abbreviated as "sin", "cos" and "tan". | + | '''Trigonometry''' is the study of angles and [[triangle]]s, relying heavily on three basic functions: [[sine]], [[cosine]] and [[tangent]], and their inverses, [[Cotangent]] (Cot), [[Secant]] (sec) and [[Cosecant]] (csc). These functions are abbreviated as "sin", "cos" and "tan". |
| | | | |
| | These functions are defined by reference to a "right triangle," which is a triangle in which one angle is 90 degrees. | | These functions are defined by reference to a "right triangle," which is a triangle in which one angle is 90 degrees. |
| Line 7: |
Line 7: |
| | *CAH: Cosine = adjacent over hypotenuse | | *CAH: Cosine = adjacent over hypotenuse |
| | *TOA: Tangent = opposite over adjacent | | *TOA: Tangent = opposite over adjacent |
| | + | |
| | + | ==Formulas== |
| | + | Complementary formulas: |
| | + | :<math>\sin(90^\circ-\alpha) \, = \, \cos\alpha</math> |
| | + | :<math>\cos(90^\circ-\alpha) \, = \, \sin\alpha</math> |
| | + | |
| | + | Pythagorean trigonometric identity: |
| | + | :<math>\sin^2\alpha + \cos^2\alpha \, = 1</math> |
| | | | |
| | ==External links== | | ==External links== |
| | *[http://id.mind.net/~zona/mmts/trigonometryRealms/introduction/rightTriangle/trigRightTriangle.html Trigonometry and Right Triangles] | | *[http://id.mind.net/~zona/mmts/trigonometryRealms/introduction/rightTriangle/trigRightTriangle.html Trigonometry and Right Triangles] |
| | | | |
| − | [[category:mathematics]] | + | [[Category:Mathematics]] |
| | + | [[Category:Trigonometry]] |