Ashwani Goyal’s Tutorial SELF ASSESSMENT TEST -2 Class 10+1 TRIGONOMETRIC FUNCTIONS 1.Evalute; (a) cos 75 (b) sin 15 2. Prove that tan 15 + cot 15 =4. 3. Prove that cot2A + tanA = cosec2A. 4. Prove that tan 75 - tan 30 - tan 75 .tan 30 = 1 5. Prove that tan3A – tan2A – tanA = tanA tan2A tan3A. 6. Prove that tan 65 = tan 25 + 2 tan 40 7. Prove that cos 29 sin 29 cos 29 sin 29 tan 74 8. If A – B = 45 , show that (1 + tanA) (1 + tanB ) = 2 tanA 9. If tanA = k tanB , then prove that sin(A-B) = 10. Prove that tan 4 k 1 sin A B k 1 tan 3 = -1 4 11. Find the value of sin(A+B), cos(A-B), tan(A-B) given that tanA = 2 , cosB = 3 5 where 180 A270 and 90 A180 . 12.Prove that sin 2 A sin 2 A 8 2 8 2 1 sin A 2 Copyright © 2013 GoyalsMath.com .All rights reserved. Ashwani Goyal’s Tutorial 13.Evaluate cos2 A sin 2 A 4 4 13 12 14. Prove that tan 15. If cos A = 1 7 =2- and cos B = 3. 13 14 ( A, B being positive acute ) , prove that A – B = 60 16. If tanA = a a 1 and tanB = 1 , 2a 1 prove A + B = 45 17.If tanA + tanB =a and cotA + cotB =b then prove that Cot (A+B) = 1 1 . a b 18. Prove that cosA – sinA = 2 cos A 4 19.If tan(A+B) = p and tan (A- B) =q then prove tan2A = 20.If cotA cotB =2 , show 21.If sin A B a b sin A B a b pq 1 pq cos A B 1 cos A B 3 , then show that tan A a tan B b 22.Prove that : cos2A cos2B + sin 2 A B sin 2 A B = cos2(A +B) 23.If 2 tanB + cotB = tanA , prove that cotB = 2 tan (A-B) 24. If cos (A +B) sin (C + D ) = cos (A – B ) sin( C- D ) , prove that CotA cotB cot C = cot D Copyright © 2013 GoyalsMath.com .All rights reserved. Ashwani Goyal’s Tutorial 25. Prove that cos 33 cos 57 21 69 sin sin 2 2 2 2 2 2 2 Copyright © 2013 GoyalsMath.com .All rights reserved.