Section 9.2: Sum and Difference Identities Video Quiz

What is the basis for the co-function identities?

• Complementary angles

• Vertical angles

• Adjacent angles

• Supplementary angles

Why is sine of an angle equal to cosine of its complement?

• Because they are vertical angles

• Because they are adjacent angles

• Because they are supplementary

• Because they are complementary

What is the property of sine when it is considered an odd function?

• sine(-x) = -cosine(x)

• sine(-x) = cosine(x)

• sine(-x) = sine(x)

• sine(-x) = -sine(x)

How can you verify that cosine is an even function using the difference formula?

• cos(0 - y) = sin(y)

• cos(0 - y) = cos(y)

• cos(0 - y) = -sin(y)

• cos(0 - y) = -cos(y)

What is the exact value of cosine(π/12) using the difference formula?

• (√3 - √2) / 4

• (√3 + √2) / 4

• (√6 - √2) / 4

• (√6 + √2) / 4

How can you express sine(11π/12) using the sum formula?

• sine(π/3 - π/4)

• sine(π/3 + π/4)

• sine(2π/3 - π/4)

• sine(2π/3 + π/4)

What is the co-function identity for sec(π/2 - θ)?

• cos(θ)

• tan(θ)

• cot(θ)

• cosec(θ)

What is the equivalent expression for tan(π/4 - x) using co-function identities?

• cot(π/4 - x)

• cot(π/4 + x)

• tan(π/4 + x)

• tan(π/4 - x)

How can you verify that sine(π/4 + x) is equivalent to cos(π/4 - x)?

• By using the Pythagorean identity

• By using the co-function identity

• By using the difference formula

• By using the sum formula

What is the equivalent expression for sin(2x) using the double angle identity?

• 2sin(x)cos(x)

• sin(x)cos(x)

• cos(x)sin(x)

• 2cos(x)sin(x)