Unit 9 simplifying trig identities

Front

What is the Pythagorean identity for sine and cosine?

Back

sin²(x) + cos²(x) = 1.

Front

What is the relationship between tangent and cotangent?

Back

tan(x) = 1/cot(x) and cot(x) = 1/tan(x).

Front

What is the formula for the cosine of the sum of two angles?

Back

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

Front

What is the formula for the sine of the sum of two angles?

Back

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

Front

What is the definition of tangent in terms of sine and cosine?

Back

tan(x) = sin(x)/cos(x).

Front

What is the definition of cotangent in terms of sine and cosine?

Back

cot(x) = cos(x)/sin(x).

Front

What is the double angle formula for sine?

Back

sin(2x) = 2sin(x)cos(x).

Front

What is the double angle formula for cosine?

Back

cos(2x) = cos²(x) - sin²(x).

Front

What is the relationship between sine and its co-function?

Back

sin(90° - x) = cos(x).

Front

What is the relationship between cosine and its co-function?

Back

cos(90° - x) = sin(x).