A) Equations that define the side lengths of a right triangle.
B) Equalities involving trigonometric functions that are true for every value of the occurring variables for which both sides are defined.
C) Calculations used exclusively for finding the area of a circle.
D) Formulas that only apply to angles in the first quadrant.

A) Trigonometric identities involve functions of angles, whereas triangle identities may involve side lengths or other lengths.
B) There is no difference; the terms are used interchangeably.
C) Triangle identities are only used in Euclidean space.
D) Trigonometric identities are always more complex than triangle identities.

A) The integration of non-trigonometric functions via substitution.
B) Simplifying algebraic polynomials without variables.
C) Determining the probability of geometric intersections.
D) Calculating the volume of non-Euclidean spheres.

A) sin² θ - cos² θ = 1
B) sin² θ + cos² θ = 1
C) sin θ + cos θ = 1
D) sin² θ + cos² θ = 0

A) x² + y² = 0
B) x + y = 1
C) x² + y² = 1
D) x² - y² = 1

A) 1 + tan² θ = sec² θ
B) sec² θ + csc² θ = 1
C) sin² θ + cos² θ = tan² θ
D) 1 + cot² θ = csc² θ

A) sin² θ + cos² θ = cot² θ
B) 1 + tan² θ = sec² θ
C) 1 + cot² θ = csc² θ
D) csc² θ + sec² θ = 1

A) θ' = 2α - θ
B) θ' = α + θ
C) θ' = 2θ - α
D) θ' = α - θ

A) 2π
B) 4π
C) π
D) π/2

A) tan θ
B) sec θ
C) cos θ
D) csc θ