R-Flashcard Identities (Basic & Sum/Diff)

Front

What is the identity for the sum of angles in cosine?

Back

The identity is: cos(A + B) = cos(A)cos(B) - sin(A)sin(B)

Front

What is the identity for the difference of angles in cosine?

Back

The identity is: cos(A - B) = cos(A)cos(B) + sin(A)sin(B)

Front

What is the Pythagorean identity?

Back

Front

What is the definition of secant?

Back

Secant is defined as: sec(x) = 1/cos(x).

Front

What is the definition of cosecant?

Back

Cosecant is defined as: csc(x) = 1/sin(x).

Front

What is the definition of cotangent?

Back

Cotangent is defined as: cot(x) = 1/tan(x) = cos(x)/sin(x).

Front

Simplify: sec(θ) cot(θ) sin(θ)

Back

The simplified result is 1.

Front

Write cos(175°)cos(55°) + sin(175°)sin(55°) as a single cosine function.

Back

This expression simplifies to cos(120°).

Front

What is the value of cos²(θ) + sin²(θ)?

Back

The value is 1.

Front

What is the relationship between sine and cosecant?

Back

csc(x) is equivalent to 1/sin(x).