Sum and Difference Identities

Front

What are the Sum and Difference Identities for sine?

Back

sin(a ± b) = sin(a)cos(b) ± cos(a)sin(b)

Front

What are the Sum and Difference Identities for cosine?

Back

cos(a ± b) = cos(a)cos(b) ∓ sin(a)sin(b)

Front

What are the Sum and Difference Identities for tangent?

Back

tan(a ± b) = (tan(a) ± tan(b)) / (1 ∓ tan(a)tan(b))

Front

Find the exact value of cos(20)cos(40) - sin(20)sin(40).

Back

1/2

Front

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

Back

cos(120)

Front

What is the value of sin(90°)?

Back

1

Front

What is the value of cos(0°)?

Back

1

Front

What is the value of tan(45°)?

Back

1

Front

If sin(a) = 1/2, what are the possible values of a?

Back

a = 30° + 360°k or a = 150° + 360°k, where k is any integer.

Front

If cos(a) = 0, what are the possible values of a?

Back

a = 90° + 180°k, where k is any integer.