Half Angle Identities

Question 1

1) tan A / 2 = ?

Answer 1

+/- (sqrt(1 - cos A / 1 + cos A))

Question 2

2) tan A / 2 = ?

Answer 2

sin A / 1 + cos A

Question 3

3) tan A / 2 = ?

Answer 3

1 - cos A / sin A

Question 4

sin A / 2 = ?

Answer 4

+/- (sqrt(1 - cos A / 2))

Question 5

cos A / 2 = ?

Answer 5

+/- (sqrt(1 + cos A / 2))