untitled

0DWK,;;)RUPD

2. (i)sin^2 θ 1 cos^2 θ
   (ii)sec^2 θ 1 tan^2 θ
   (iii)cot^2 θ 1 tan^2 θ
   Which one of the followings is correct in accordance with the above statements.
   (a) i and ii (b) i and iii (c) ii and iii (d) i, ii and iii

Answer of questions 3 and 4 on the basis of the figure :

3. What is the value of sinθ?

(a)

4

3

(b)

3

4

(c)

5

3

(d)

5

4

4. What is the value of cotθ?

(a)

4

3

(b)

5

3

(c)

5

4

(d)

3

4

Evaluate (5 – 8) :

5. $

$

1 cot 60

1 cot 60

2

2





.

6. tan 45 $˜sin^260 $˜tan 30 $˜tan 60 $.


7. $ $

$

sec 60

1 cos 60

1 cos (^602)
2
2



.

8. 
   

   cos 45 $˜cot^260 $˜cosec^230 $.
   Prove (9 – 11) :

   
   


9. 
   

   cos^230 $sin^230 $ cos 60 $.

   
   


10. 
    

    sin 60 $cos 30 $cos 60 $sin 30 $ sin 90 $.

    
    


11. 
    

    cos 60 $cos 30 $sin 60 $sin 30 $ cos 30 $.

    
    


12. 
    

    sin 3 A cos 3 A, if`A 15 $.

    
    


13. 
    

    1 tanA

    
    

2 tanA

sin 2 A 2



, if A 45 $.

14. ta A

taA

ta A 2

1 n

2 n

n 2



, if A 30 $.

15. 1 tanA

1 tanA

cos 2 A 2

2





, if A 60 $.

16. If 2 cos(AB) 1 2 sin(AB) and A,B are acute angles, show that A 45 $,

B 15 $.