How to Prove tan(a - b) = tana - tanb without using a prefix?

  • Thread starter Thread starter Quinn Morris
  • Start date Start date
  • Tags Tags
    Formulas Trig
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
Sign up Log in
3 replies · 3K views
Quinn Morris
Messages
14
Reaction score
0

Homework Statement



Prove that: tan (a - b) = tana - tanb
1 + tanatanb​
]​

Homework Equations



cos (a- b) = cosacosb + sinasinb


sin (a - b) = sinacosb - cosasinb


The Attempt at a Solution



I have plugged in the two equations give above since tan - sin/cos and then I'm am stumped of how to proceed

tan (a - b) = sinacosb - cosasinb
cosacosb + sinasinb​

can anyone help please?
 
Physics news on Phys.org

Discussion

Quinn Morris said:
tan (a - b) = sinacosb - cosasinb
cosacosb + sinasinb​

The formula you are trying to arrive at provides the clue: what could you divide numerator and denominator by to get that "1" in the denominator?