Posted by Pre Calculus on .
Pre Calculus
why is sin(20)/cos 380
equal to tan (200)

Pre Calculus 
bobpursley,
I covered this previously.
Sin(theta)=sin(theta+360) in degrees
Sin(theta)=sin(Theta) in degrees
sin(20)=sin(20) =sin(20+360)=sin(380)
then...
Tan(theta)=tan(theta).
Your refusal to post some sort of a meaningful name in the name box is not helping you get meaningful assistance.