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Expressions can be very complex, and it is possible to combine mathematic functions (sine, cosine, square root, etc.), and perform calculations (addition, multiplication, etc). Under “Insert” you will find drop-down lists with the entire range of elements. Expressions are a fast and convenient method, but it can be difficult to create specific behaviour by combining functions like sine or cosine. In situations like that you should consider → drawing curves.
Another effect you can see with predefined functions is that the curve is increasing or decreasing, as shown in the sine curve below:
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