Trigonometric Identities

sin²x = (cos identity)

1 - cos²x

cos²x = (sin identity)

1 - sin²x

sec²x = (tan identity)

tan²x + 1

tan²x = (sec identity)

sec²x - 1

csc²x = (cot identity)

cot²x + 1

cot²x = (csc identity)

csc²x - 1

Write all possible equations that sum/diff up to 1.

sin²x + cos²x, sec²x - tan²x, csc²x - cot²x

sin(2x) =

2sin(x)cos(x)

cos(2x) = (three answers)

cos²(x) - sin²(x), 2cos²(x) - 1, 1 - 2sin²(x)

sin²θ = (long identity)

½(1 - cos(2θ))

cos²θ = (long identity)

½(1 + cos(2θ))