Question 819659
Ans:
Since tan(A-B) = [tan(A)-tan(B)]/[1+tan(A)tan(B)]
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the exact value of the expression  
[Tan(105)-tan(-15)]/[1+Tan(105)Tan(-15)]
is tan[105-(-15)]
= tan[120)
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Cheers,
Stan H.
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