Trigonometry Flashcards

What is the value of sin(π/6)?

Answer: 1/2

π/6 = 30°, and sin(30°) = 1/2 from the standard unit circle values.

What is the value of cos(π/2)?

Answer: 0

π/2 = 90°, and cos(90°) = 0 because the x-coordinate at the top of the unit circle is 0.

What is tan(π/4)?

Answer: 1

π/4 = 45°, and tan(45°) = sin(45°)/cos(45°) = 1 because sine and cosine are equal at this angle.

Which expression equals sin(2θ) according to the double angle formula?

Answer: 2sin(θ)cos(θ)

The double angle formula for sine is sin(2θ) = 2sin(θ)cos(θ).

What is the period of y = cos(2x)?

Answer: π

For y = cos(Bx), the period is 2π/B; with B = 2, the period is 2π/2 = π.

Which expression is equivalent to 1 + tan²(θ)?

Answer: sec²(θ)

Dividing the identity sin²(θ) + cos²(θ) = 1 by cos²(θ) yields tan²(θ) + 1 = sec²(θ).

What is the value of cos(π)?

Answer: −1

At π radians (180°), the point on the unit circle is (−1, 0), so cos(π) = −1.