How do you evaluate tan ((2pi)/3)tan(2π3)?

1 Answer
Dec 4, 2016

tan((2pi)/3)=-sqrt3tan(2π3)=3

Explanation:

tan((2pi)/3)tan(2π3)

Recall the identity tantheta=sintheta/costhetatanθ=sinθcosθ

According to the unit circle,

sin((2pi)/3)=sqrt3/2sin(2π3)=32 and cos((2pi)/3)=-1/2cos(2π3)=12

tan((2pi)/3) =frac{sin((2pi)/3)}{cos((2pi)/3)}=frac(sqrt3/2)(-1/2)tan(2π3)=sin(2π3)cos(2π3)=3212

=sqrt3/2 * -2/1=sqrt3/cancel2 * -cancel2/1=-sqrt3