Looking for accurate SEBA Class 10 Maths Exercise 8.3 (Introduction to Trigonometry) textual solutions for the 2026-27 academic year? Access complete step-by-step solutions covering fundamental trigonometric identities (sin^2 theta + cos^2 theta = 1, 1 + tan^2 theta = sec^2 theta, 1 + cot^2 theta = cosec^2 theta), expressing trigonometric ratios in terms of other ratios, and proving complex identities to score top marks in your HSLC board exams.
EXERCISE 8.3
1. Evaluate:
(i) sin 18° / cos 72°
(ii) tan 26° / cot 64°
(iii) cos 48° – sin 42°
(iv) cosec 31° – sec 59°
(v) sin 35° sin 55° – cos 35° cos 55°
(vi) tan 35° tan 60° tan 55° tan 30°
(vii) (cot 54° / tan 36°) + (tan 20° / cot 70°) – 2
(viii) 3 (sin 23° / cos 67°) + 4 (sec 47° / cosec 43°)
(ix) tan 5° tan 25° tan 30° tan 65° tan 85°
SEBA Class 10 Maths Exercise 8.3 Solutions
2. Show that:
(i) tan 48° tan 23° tan 42° tan 67° = 1
(ii) cos 38° cos 52° – sin 38° sin 52° = 0
Class 10 Maths Chapter 8 Exercise 8.3 Question Answer SEBA 2026-27
3. If tan 2A = cot(A – 18°), where 2A is an acute angle, find the value of A.
4. If tan A = cot B, prove that A + B = 90°.
Trigonometric Identities Proofs Class 10 SEBA Ex 8.3 Solutions
5. If sec 4A = cosec(A – 20°), where 4A is an acute angle, find the value of A.
6. (i) If A, B and C are interior angles of a triangle ABC, then show that: sin((B + C) / 2) = cos(A / 2)
(ii) If A, B, C are interior angles of Triangle ABC, prove that: tan((B + C) / 2) = cot(A / 2)
SEBA Class 10 Maths Chapter 8 Exercise 8.3 Textbook Answers
7. Express sin 67° + cos 75° in terms of trigonometric ratios of angles between 0° and 45°.
(i) If sec 5theta = cosec(theta – 36°) where theta is an acute angle, then find the value of theta.
(ii) If sin A = cos 33°, A < 90°. Find the value of A.
(iii) If sin 2A = cos(A + 15°) where 2A < 90°, find the value of A.
(iv) If sin(3x + 10°) = cos(x + 24°) then find the value of x.
Class 10 Maths Exercise 8.3 Prove Trigonometric Identities
📐 Updated Solutions Notice: This page features complete, step-by-step SEBA Class 10 Mathematics Chapter 8 (Introduction to Trigonometry) Exercise 8.3 Textual Solutions updated for the 2026–27 academic session. All fundamental trigonometric identity proofs, algebraic conversions ($\sin\theta$, $\cos\theta$, $\tan\theta$), and LHS-to-RHS trigonometric evaluations strictly follow the latest revised Assam Board (SEBA/ASSEB) curriculum.
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