LaTeX 中表示角度的幾種方法

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The cosine of 90 degrees is $\cos(90\degree) = 0$.

The cosine of 90 degrees is $\cos(90\textdegree) = 0$.

The cosine of 90 degrees is cos(90\textdegree) = 0.

The cosine of 90 degrees is $\cos(90^{\circ}) = 0$.

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