NCERT class 10 maths chapter 8 Introduction To Trigonometry
Question 1:Evaluate the following : (i) sin 60° cos 30° + sin 30° cos 60° (ii) 2 tan2 45° + cos2 30° – sin2 60° (iii) cos 45° sec 30° + cosec 30° (iv) sin 30° + tan 45° – cosec 60° sec 30° + cos 60° + cot 45° (v) 2 2 2 2 2 5 cos 60 4 sec 30 tan 45 sin 30 cos 30 ° + ° − ° ° + °
Exercise 8.2 maths class 10 Chapter 8 Introduction To Trigonometry
Question 2:Choose the correct option and justify your choice : (i) 2 2 tan 30 1 tan 30 ° = + ° (A) sin 60° (B) cos 60° (C) tan 60° (D) sin 30° (ii) 2 2 1 tan 45 1 tan 45 − ° = + ° (A) tan 90° (B) 1 (C) sin 45° (D) 0 (iii) sin 2A = 2 sin A is true when A = (A) 0° (B) 30° (C) 45° (D) 60° (iv) 2 2 tan 30 1 tan 30 ° = − ° (A) cos 60° (B) sin 60° (C) tan 60° (D) sin 30°
CBSE class 10 maths ncert solutions Chapter 8
Question 3:If tan (A + B) = 3 and tan (A – B) = 1 3 ; 0° < A + B ≤ 90°; A > B, find A and B.
Question 4:State whether the following are true or false. Justify your answer. (i) sin (A + B) = sin A + sin B. (ii) The value of sin q increases as q increases. (iii) The value of cos q increases as q increases. (iv) sin q = cos q for all values of q. (v) cot A is not defined for A = 0°.