Which of the following equations are identities? a) tan x = cos x/ sin x b) csc x = 1/ sin x c) cot x = 1/ tan x d) sec x = 1/ csc x

we have that

case A) tan x = cos x/ sin x> is not a identity

the correct identity is

tan x=sin x/cos x> is a ratio identity

case B) csc x = 1/ sin x> is a identity (Reciprocal identity)

case C) cot x = 1/ tan x > is a identity (Reciprocal identity)

case D) sec x = 1/ csc x> is not a identity

the correct identity is

sec x=1/cos x> is a Reciprocal identity

therefore

the answer is

B) csc x = 1/ sin x

C) cot x = 1/ tan x