SOLUTION: I'm not really understanding using the Sum and Difference Formulas to find Exact values. Maybe I just need some more in depth explanation of how it works but I'm having a hard time

Question 819659: I'm not really understanding using the Sum and Difference Formulas to find Exact values. Maybe I just need some more in depth explanation of how it works but I'm having a hard time finding the exact value of expression of Tan(105)-tan(-15)/1+Tan(105)Tan(-15)
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
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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