Difference between revisions of "Cosine"
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'''Cosine''' is a [[trigonometric function]] describing the [[ratio]] of the adjacent side to the [[hypotenuse]] in a [[right triangle]]. It is often abbreviated ''cos''. | '''Cosine''' is a [[trigonometric function]] describing the [[ratio]] of the adjacent side to the [[hypotenuse]] in a [[right triangle]]. It is often abbreviated ''cos''. | ||
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| + | {| style="background:none" | ||
| + | | | ||
| + | {| class="wikitable" style="text-align:center" | ||
| + | |- | ||
| + | !x values | ||
| + | !y values | ||
| + | |- | ||
| + | |width="50%"|0 | ||
| + | |width="50%"|1 | ||
| + | |- | ||
| + | |π/2 | ||
| + | |0 | ||
| + | |- | ||
| + | |π | ||
| + | | -1 | ||
| + | |- | ||
| + | |3π/2 | ||
| + | | 0 | ||
| + | |- | ||
| + | |2π | ||
| + | |1 | ||
| + | |} | ||
| + | |[[Image:Cosine-pi.jpg]] | ||
| + | |} | ||
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| + | 2π [[radians]] is equivalent to one circle. The graph continues in that pattern. | ||
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| + | ==Relation to secant== | ||
<math>\cos \theta = \sin \left(\frac{\pi}{2} - \theta \right) = \frac{1}{\sec \theta}\,</math> | <math>\cos \theta = \sin \left(\frac{\pi}{2} - \theta \right) = \frac{1}{\sec \theta}\,</math> | ||
| − | [[Category: | + | [[Category:Trigonometry]] |
Latest revision as of 12:19, December 8, 2008
Cosine is a trigonometric function describing the ratio of the adjacent side to the hypotenuse in a right triangle. It is often abbreviated cos.
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2π radians is equivalent to one circle. The graph continues in that pattern.
Relation to secant
<math>\cos \theta = \sin \left(\frac{\pi}{2} - \theta \right) = \frac{1}{\sec \theta}\,</math>