Identity Properties of Sine, Cosine, Tangent, Cosecant, Secant, and Cotangent

Reciprocal and Quotient ID: sec () =

1/cos ()

Reciprocal and Quotient ID: tan () =

1/cot ()

Reciprocal and Quotient ID: sin () =

1/csc ()

Reciprocal and Quotient ID: cos () =

1/sec ()

Reciprocal and Quotient ID: csc () =

1/sin ()

Reciprocal and Quotient ID: cot () =

1/tan ()

Odd-Even ID: Cosines?

cos [ -() ] = cos ()

Cofunction ID: sin () =

cos [ 2/pi - () ]

Odd-Even ID: Cotangents?

cot [ -() ] = -cot ()

Cofunction ID: tan () =

cot [ 2/pi - () ]

Pythagorean ID: cotangents and cosecants?

cot^2 () + 1 = csc^2 ()

Odd-Even ID: Cosecants?

csc [ -() ] = -csc ()

Cofunction ID: sec () =

csc [ 2/pi - () ]

Odd-Even ID: Secants?

sec [ -() ] = sec ()

Cofunction ID: csc () =

sec [ 2/pi - () ]

Odd-Even ID: Sines?

sin [ -() ] = -sin ()

Cofunction ID: cos () =

sin [ 2/pi - () ]

Pythagorean ID: sines and cosines?

sin^2 () + cos^2 () = 1

Odd-Even ID: Tangents?

tan [ -() ] = -tan ()

Cofunction ID: cot () =

tan [ 2/pi - () ]

Pythagorean ID: tangents and secants?

tan^2 () + 1 = sec^2 ()