trigonometry

Question 1

what does tan^2x=?

Answer 1

sec^2(x)-1

Question 2

what is sin(2x)?

Answer 2

2sin(x)cos(x)

Question 3

what is cos(2x)?

Answer 3

1. cos^2(x)-sin^2(x)
2. 1-2sin^2(x)
3. 2cos^2(x)-1

Question 4

what is tan(2x)?

Answer 4

2tan(x)

1-tan^2(x)