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2.8 Calculating Trigonometric FunctionsNN 2, IE 3 2.8.1 ProblemYou want to invoke a variety of trigonometric functions, perhaps for calculating animation paths of a positioned element. 2.8.2 SolutionJavaScript's Math object comes with a typical complement of functions for trigonometric calculations. Each one requires one or two arguments and returns a result in radians. Arguments representing angles must also be expressed in radians. The following statement assigns the sine of a value to a variable: var sineValue = Math.sin(radiansInput); All Math object methods must be invoked as methods of the static Math object. 2.8.3 DiscussionSee the introduction to this chapter for a summary of all Math object methods and constants. You can see an application of trigonometric functions in Recipe 13.10, which calculates the circular path for a positioned element to follow on the page. 2.8.4 See AlsoSection 2.0.2 in the introduction of this chapter; Recipe 13.10 where some trigonometric operations help calculate points around a circular path. |
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