Write cos2x in terms of sinx

1+ 2sin²x

1-2sin²x

1+sin²x

1-sin²x

Write cos2x in terms of cosx

2cos²x + 1

cos²x -1

2cos²x - 1

cos²x + 1

Write sin²x in terms of cos2x

½(1 + cos2x)

½(1 - cos2x)

½cos2x

1 - cos2x

Write cos²x in terms of cos2x

½(cos2x + 1)

½(cos2x - 1)

cos2x -1

cos2x + 1

Express cos2x in terms of sinx and cosx

cos²x - sin²x

cos²x + sin²x

sin²x - cos²x

2cos²x - sin²x

Express sin2x in terms of sinx and cosx

2sinxcosx

2sinx + cosx

2cosx + sinx

2(sinx + cosx)

secx =

1/cosx

1/sinx

1/tanx

cosecx =

cotx =

What is the small angle approximation for sinθ?

θ

2θ

1 - θ

1 - 2θ

What is the small angle approximation for cosθ?

1 - θ²/2

1 - θ²

θ²

What is the small angle approximation for tanθ?

1 + θ

θ - 1