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Cos




Mathematica Notation

Traditional Notation









Elementary Functions > Cos[z] > Transformations > Products, sums, and powers of the direct function > Sums of the direct function





http://functions.wolfram.com/01.07.16.0100.01









  


  








Input Form





Cos[a] + Cos[b] == 2 Cos[(a - b)/2] Cos[(a + b)/2]








Standard Form





Cell[BoxData[RowBox[List[RowBox[List[RowBox[List["Cos", "[", "a", "]"]], "+", RowBox[List["Cos", "[", "b", "]"]]]], "\[Equal]", RowBox[List["2", " ", RowBox[List["Cos", "[", FractionBox[RowBox[List["a", "-", "b"]], "2"], "]"]], " ", RowBox[List["Cos", "[", FractionBox[RowBox[List["a", "+", "b"]], "2"], "]"]]]]]]]]








MathML Form







<math xmlns='http://www.w3.org/1998/Math/MathML' mathematica:form='TraditionalForm' xmlns:mathematica='http://www.wolfram.com/XML/'> <semantics> <mrow> <mrow> <mrow> <mi> cos </mi> <mo> &#8289; </mo> <mo> ( </mo> <mi> a </mi> <mo> ) </mo> </mrow> <mo> + </mo> <mrow> <mi> cos </mi> <mo> &#8289; </mo> <mo> ( </mo> <mi> b </mi> <mo> ) </mo> </mrow> </mrow> <mo> &#10869; </mo> <mrow> <mn> 2 </mn> <mo> &#8290; </mo> <mrow> <mi> cos </mi> <mo> &#8289; </mo> <mo> ( </mo> <mfrac> <mrow> <mi> a </mi> <mo> - </mo> <mi> b </mi> </mrow> <mn> 2 </mn> </mfrac> <mo> ) </mo> </mrow> <mo> &#8290; </mo> <mrow> <mi> cos </mi> <mo> &#8289; </mo> <mo> ( </mo> <mfrac> <mrow> <mi> a </mi> <mo> + </mo> <mi> b </mi> </mrow> <mn> 2 </mn> </mfrac> <mo> ) </mo> </mrow> </mrow> </mrow> <annotation-xml encoding='MathML-Content'> <apply> <eq /> <apply> <plus /> <apply> <cos /> <ci> a </ci> </apply> <apply> <cos /> <ci> b </ci> </apply> </apply> <apply> <times /> <cn type='integer'> 2 </cn> <apply> <cos /> <apply> <times /> <apply> <plus /> <ci> a </ci> <apply> <times /> <cn type='integer'> -1 </cn> <ci> b </ci> </apply> </apply> <apply> <power /> <cn type='integer'> 2 </cn> <cn type='integer'> -1 </cn> </apply> </apply> </apply> <apply> <cos /> <apply> <times /> <apply> <plus /> <ci> a </ci> <ci> b </ci> </apply> <apply> <power /> <cn type='integer'> 2 </cn> <cn type='integer'> -1 </cn> </apply> </apply> </apply> </apply> </apply> </annotation-xml> </semantics> </math>










Rule Form





Cell[BoxData[RowBox[List[RowBox[List["HoldPattern", "[", RowBox[List[RowBox[List["Cos", "[", "a_", "]"]], "+", RowBox[List["Cos", "[", "b_", "]"]]]], "]"]], "\[RuleDelayed]", RowBox[List["2", " ", RowBox[List["Cos", "[", FractionBox[RowBox[List["a", "-", "b"]], "2"], "]"]], " ", RowBox[List["Cos", "[", FractionBox[RowBox[List["a", "+", "b"]], "2"], "]"]]]]]]]]


Date Added to functions.wolfram.com (modification date)





2001-10-29