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May 6, 2016
Posted by **-** on Saturday, November 7, 2009 at 8:27pm.

can be written as:

tan(x-y) = (tanx - tany) / (1+ tanxtany)

- adv functions -
**Reiny**, Saturday, November 7, 2009 at 11:18pmwrite tan (x-y)

= sin(x-y)/cos(x-y)

= [sinxcosy - cosxsiny[/[cosxcosy + sinxsiny]

Now divide everybody by cosxcosy and it will all fall into place.