Display Function Identities 

It is easier than ever to display function identities.

Odd functions.

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X Block[{e = Inactivate[Sin[-x], Sin]}, e == Activate[e]] // TraditionalForm

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X Block[{e = Inactivate[Sinh[-x], Sinh]}, e == Activate[e]] // TraditionalForm

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Even functions.

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X Block[{e = Inactivate[Cos[-x], Cos]}, e == Activate[e]] // TraditionalForm

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X Block[{e = Inactivate[Cosh[- x], Cosh]}, e == Activate[e]] // TraditionalForm

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Plots that illustrate these properties.

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X Row[{Plot[{Sin[x], Cos[x]}, {x, -Pi, Pi}, PlotLegends -> Placed["Expressions", Below]], Plot[{Sinh[x], Cosh[x]}, {x, -2, 2}, PlotLegends -> Placed["Expressions", Below]]}]

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Hyperbolic functions with imaginary arguments are equivalent to trigonometric functions.

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X Block[{e = Inactivate[Sinh[I x], Sinh]}, e == Activate[e]] // TraditionalForm

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X Block[{e = Inactivate[Cosh[I x], Cosh]}, e == Activate[e]] // TraditionalForm

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