Question

Which of the following are trigonometric identities? More than 1 answer:

A. 1-cot(x) tan(y)=sin(x+y)/ sin(x) cos(y)
B. 4cos(x) sin(x)=2cos(x)+1-2sin(x)
C. tan(x) cos(x) csc(x)=1
D. csc(x)-sin(x)/csc(x)=cos²x

Answer 1

I'm pretty sure c. is one of the answers

Answer 2

i agree..

Answer 3

is there another answer though since it says more than one answer?

Answer 4

I'm thinking a?

Answer 5

fastest way (i think) is to graph the left side and right side at the same time... if they produce the same graph, then they are identities...

Answer 6

d is not..

Answer 7

so its definitely C. and either A or B?

Answer 8

B is not..

Answer 9

b is not..

Answer 10

try x=0

Answer 11

ah it was a. c. and d.

Answer 12

yea.. i just found A to be an identity..