Chapter 3,

Chapter 3, "Trigonometry Snippets"

Degrees to Radians

Angle in degrees * = angle in radians.

Radians to Degrees

Angle in radians * = angle in degrees.

Trigonometric Functions

where opp = the side opposite a , adj = the side adjacent to a , and hyp = the hypotenuse .

Other Trigonometric Functions

where opp = the side opposite a , adj = the side adjacent to a , and hyp = the hypotenuse.

Period of the Sine Wave

For y = sin( Bx ), the period = .

Amplitude of the Sine Wave

For y = A sin( x ), the amplitude = A .

Unit Circle Identity

cos ² a + sin ² a = 1

Tangent and Cotangent

Negative Angles

sin( “ a ) = “sin a

cos( “ a ) = cos a

tan( “ a ) = “tan a

Sum and Difference Identities for Sine

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

sin( a ₁ “ a ₂ ) = sin a ₁ cos a ₂ “ cos a ₁ sin a ₂

Sum and Difference Identities for Cosine

cos( a ₁ + a ₂ ) = cos a ₁ cos a ₂ “ sin a ₁ sin a ₂

cos( a ₁ “ a ₂ ) = cos a ₁ cos a ₂ + sin a ₁ sin a ₂