Basic Trig Identities

Front

What is the definition of cosine (cos x)?

Back

Cosine is the ratio of the adjacent side to the hypotenuse in a right triangle.

Front

What is the definition of sine (sin x)?

Back

Sine is the ratio of the opposite side to the hypotenuse in a right triangle.

Front

What is the definition of tangent (tan x)?

Back

Tangent is the ratio of the opposite side to the adjacent side in a right triangle.

Front

What is the relationship between secant (sec x) and cosine (cos x)?

Back

sec x = 1/cos x.

Front

What is the relationship between cosecant (csc x) and sine (sin x)?

Back

csc x = 1/sin x.

Front

What is the relationship between cotangent (cot x) and tangent (tan x)?

Back

cot x = 1/tan x.

Front

What is the Pythagorean identity involving sine and cosine?

Back

sin²x + cos²x = 1.

Front

What is the value of cos(0°)?

Back

1.

Front

What is the value of sin(90°)?

Back

1.

Front

What is the value of tan(45°)?

Back

1.