you lost me here. i get the 1/cos(x) but where are you getting sin(x)/cos(x) from? i'm guessing this is some other identity than tangent is equal to?? i think what it is is my textbook only covers the basics.

here is what i have:

sin(x) = [1/csc(x)]

cos(x) = [1/sec(x)]

tan(x) = [1/cot(x)]

csc(x) = [1/sin(x)]

sec(x) = [1/cos(x)]

cot(x) = [1/tan(x)]

cos^2(x) + sin^2(x) = 1

tan^2(x) + 1 = sec^2(x)

1 + cot^2(x) = csc^2(x)

sin(x/2) =

[1-cos(x) / 2]

cos(x/2) =

[1+cos(x) / 2]

tan(x/2) =

[1-cos(x) / 1 + cos(x)]

sin(2x) = [2sin(x)][cos(x)]

cos(2x) = [cos^2(x)] - [sin^2(x)]

= [2cos^2(x)] - 1

= 1 - [2sin^2(x)]

tan(2x) = [(2)(tan(x))] / [1-tan^2(x)]

cos(x

y) = [cos(x)][cos(y)]

[sin(x)][sin(y)]

sin(x

y) = [sin(x)][cos(y)]

[sin(y)][cos(x)]

tan(x

y) = [tan(x)

tan(y)] / [1

[tan(x)][tan(y)]]

can you take a look at this and tell me what i'm missing?? because i think that's why i can't do anything with my homework.