can someone explain to me this

tan 45 - tan 30
_________________
1 + tan 140 tan 60 = tan (45 - 30)

answer = tan 15

okay I understand how was 15 used but what about
the bottom of the fraction?
1 + tan 140 tan 60??

Question

can someone explain to me this

tan 45 - tan 30
_________________
1 + tan 140 tan 60  =        tan  (45 - 30)

                     answer = tan 15
 
okay I understand how was 15 used but what about 
the bottom of the fraction?  
1 + tan 140 tan 60??

anonymous · Answer

That entire fraction is equivalent to tan 15 degrees.

anonymous · Answer

That is tan (45-30) = [tan 45 - tan 30]/[1+tan45 tan 30]

anonymous · Answer

I dont know where you are getting 1+ tan 140 tan 60 from.

anonymous · Answer

oh, well that how its written in the book

the whole problem is 
tan 45 - tan 30
_________________
1 + tan 140 tan 60

anonymous · Answer

I have no idea where they get that denominator from.

The formula for tan(45-30) is what i wrote in my earlier post.

anonymous · Answer

make sure you are typing it correctly from your textbook.

anonymous · Answer

The denominator should read 1 + tan(45) tan(30)

anonymous · Answer

ohhhhh okay i double check now, sorry 
i wrote it wrong

its    tan 45 - tan 30
        _________________
       1 + tan 45 tan 30



sorry!!!!!!

anonymous · Answer

OK. Now everything is cleared up.

anonymous · Answer

Now, that formula is correct!

anonymous · Answer

okay, sorry thanks again!

anonymous · Answer

welcome.