Why delphi 7 has no (trigonometry) tan?
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I was about to make a projectile motion calculator but I noticed that `tan` is not declared. <br>[this][1] pointed me that it should be declared
<br> Where is it and why isn't it in standard lib?<br>


  [1]: http://www.delphibasics.co.uk/RTL.asp?Name=Tan