Question

Which of the following are identities. Check all that apply.

A. cos (x + pi/6) = -sin (x - pi/3)
B. 1- tan(x) tan(y) = sin (x+y) / sin(x) sin(y)
C. tan(x) -tan(y) = sin (x - y) / cos(x) cos(y)
D. tan (x-pi/4) = tan x-1

***My Answer: A***
Are there any other possibilities? Please help.

Answer 1

yup for A

Answer 2

Awesome

Answer 3

i think dat sit/

Answer 4

Ok that's what I got too.

I hit the submit button and it told me that A and C were it. Thank you for your help!