PLEASE HELP FAST!!

To verify the identity tan(x1+x2+x3)= tanx1+tanx2+tanx3-tanx1tanx2tanx3/1-tanx1tanx2-tanx2tanx3-tanx1tanx3, what should you do first?

Respuesta :

Hello,
Please, see the attached file.
Thanks.
Ver imagen Professor1994