Master How to evaluate using the cofunction identities

The video tutorial provides an introduction to cofunction identities in trigonometry, explaining their significance and how they relate to the unit circle. It covers the relationships between sine and cosine, tangent and cotangent, and cosecant and secant, demonstrating how these identities can simplify calculations and problem-solving in tests or without a unit circle. The tutorial emphasizes the importance of recognizing these identities for efficient problem-solving.

What is the cofunction identity for sine in terms of cosine?

• sin(θ) = cos(90° - θ)

• sin(θ) = tan(90° - θ)

• sin(θ) = cot(90° - θ)

• sin(θ) = sec(90° - θ)

If the tangent of an angle is known, what is the cofunction identity for cotangent?

• cot(θ) = cos(90° - θ)

• cot(θ) = sin(90° - θ)

• cot(θ) = tan(90° - θ)

• cot(θ) = sec(90° - θ)

How can recognizing cofunction identities be beneficial during a test?

• They help in drawing the unit circle.

• They allow quick calculations without the unit circle.

• They provide exact values for all angles.

• They eliminate the need for any calculations.

What is the cofunction identity for cosecant in terms of secant?

• csc(θ) = sec(90° - θ)

• csc(θ) = tan(90° - θ)

• csc(θ) = cot(90° - θ)

• csc(θ) = cos(90° - θ)

What is the secant of 0 degrees according to the cofunction identity?

• 1

• 0

• Undefined

• -1