Choosing Trig Functions

Front

What is the definition of sine in a right triangle?

Back

Sine (sin) is the ratio of the length of the opposite side to the length of the hypotenuse. Formula: sin(θ) = opposite/hypotenuse.

Front

What is the definition of cosine in a right triangle?

Back

Cosine (cos) is the ratio of the length of the adjacent side to the length of the hypotenuse. Formula: cos(θ) = adjacent/hypotenuse.

Front

What is the definition of tangent in a right triangle?

Back

Tangent (tan) is the ratio of the length of the opposite side to the length of the adjacent side. Formula: tan(θ) = opposite/adjacent.

Front

If you know the opposite side and hypotenuse, which trig function do you use?

Back

Sine (sin) is used when you know the opposite side and hypotenuse.

Front

If you know the adjacent side and hypotenuse, which trig function do you use?

Back

Cosine (cos) is used when you know the adjacent side and hypotenuse.

Front

If you know the opposite side and adjacent side, which trig function do you use?

Back

Tangent (tan) is used when you know the opposite side and adjacent side.

Front

What is the sine ratio for an angle of 30 degrees?

Back

sin(30°) = 1/2.

Front

What is the cosine ratio for an angle of 60 degrees?

Back

cos(60°) = 1/2.

Front

What is the tangent ratio for an angle of 45 degrees?

Back

tan(45°) = 1.

Front

What is the Pythagorean identity involving sine and cosine?

Back

The Pythagorean identity states that sin²(θ) + cos²(θ) = 1.