68 practice questions on Trigonometric Functions , sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Trigonometric Functions notes .
x y 0 deg 30 deg 45 deg (1/sqrt2, 1/sqrt2) 60 deg 90 deg cos45 sin45 Unit circle with standard angles 0, 30, 45, 60, 90 degrees; at 45 degrees the point is (cos45, sin45) = (1/sqrt2, 1/sqrt2).
Easy - 20 questions Q4.
The fundamental trigonometric identity is:
A sin²θ - cos²θ = 1B sin²θ + cos²θ = 1C sinθ × cosθ = 1D sinθ + cosθ = 1Show answer & explanation →
Medium - 20 questions Q22.
Prove that (1+tanθ)² + (1+cotθ)² = (secθ + cosecθ)². LHS equals:
A sec²θ + cosec²θB 2 + 2tanθ + 2cotθ + tan²θ + cot²θC (secθ+cosecθ)²D All are equalShow answer & explanation →
Q34.
cos 2A = 1 - 2sin²A. Verify for A = 30°:
A cos 60° = 1/2 and 1-2sin²30° = 1/2 (true)B cos 60° = √3/2, mistakenly using the cos 30° value insteadC They are not equal, since sin²30° was computed as 3/4 in errorD The identity only works for A = 0, where both sides trivially vanishShow answer & explanation →
Q40.
In a triangle, if a = 5, b = 6, c = 7, use the cosine rule to find angle A:
A cos A = 60/84B cos A = 5/7C cos A = 10/12D cos A = 60/60Show answer & explanation →
Hard - 28 questions Q41.
Solve: 2cos²θ - 3cosθ + 1 = 0. Find all solutions in [0, 2π].
A 0, π/3, 5π/3, 2πB 0, π/3, πC π/3, π, 5π/3D 0, 2π/3, 4π/3Show answer & explanation →
Q44.
General solution of 2cos²x + 3sinx = 0 is:
A x = nπ + (-1)<sup>n</sup> × 7π/6, an incorrect general formB x = nπ + (-1)<sup>n</sup> × (-π/6), using the wrong reference angleC x = 7π/6 + 2nπ or x = 11π/6 + 2nπD No solution exists within the given range of valuesShow answer & explanation →
Q45.
tan(A+B+C) formula: if A+B+C = π, then tanA + tanB + tanC =
A 0, assuming the angles cancel outB 1, treating the identity as trivialC tanA tanB tanCD π, confusing it with the angle sumShow answer & explanation →
Q54.
Solve tan²θ - 3 = 0 for θ in (0, 2π).
A π/3, 2π/3, 4π/3, 5π/3B π/3, π/3 + π, missing two of the four valid solutionsC π/6, 5π/6, using the wrong reference angleD π/3, treating it as the single unique solutionShow answer & explanation →
Q57.
In triangle, sin(A/2) = √[(s-b)(s-c)/bc]. This is:
A Tangent half-angle formula expressed using the semi-perimeter sB Half-angle sine formula using s (semi-perimeter)C A variant of the cosine rule rearranged in terms of sD Projection formula relating a side to the cosines of the other anglesShow answer & explanation →