APPC review

Sin(u/2)

±√[(1 - cos(u))/2]

Sin(2u)

2sin(u)cos(u)

Sin(a+b)

sin(a)cos(b) + cos(a)sin(b).

sin(a-b)

sin(a)cos(b) - cos(a)sin(b)

Cos(u/2)

±√[(1 + cos(u))/2]

cos(2u)

cos²(u) - sin²(u)

cos(2u)

1-2sin²u

cos(2u)

2cos²u-1

cos(a+b)

cos(a)cos(b) - sin(a)sin(b)

cos(a-b)

cos(a)cos(b) + sin(a)sin(b)

tan(u/2)

±√[(1 - cos(u))/(1+cos(u)]

tan(2u)

[(2tan(u))/1-tan²u)]

tan(a+b)

(tan a + tan b) / (1 - tan a * tan b)

tan(a-b)

(tan a - tan b) / (1 + tan a * tan b)

Pythagorean identities

sin²x+cos²x=1

1+tan²x=sec²

1+cot²x=csc²

Reciprocal Identities

1/sin=csc

1/cos=sec

1/tan=cot

1/csc=sin

1/sec=cos

1/cot=tan