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8. Introduction to Trigonometry

Trigonometry

Chapter 8. Introduction of Trigonometry

Class 10 Maths Chapter 8 Introduction of Trigonometry : Multiple Choice Questions , Answer following the Questions , Fill in the blanks , 2 Marks Questions , 3 Marks Question , 4 Marks and Solutions :    

Class 10 Introduction of Trigonometry Multiple Choice Questions and Solutions

SECTION = A

Q1.   

(a)                               

 (b)                       

(c)                         

(d)                                

Solution:  (b)   .                     

[ We have ,          ]

Q2.    

(a) tan90°                          

(b) 1                                   

(c)  sin45°                       

(d)  0 

Solution:   (d)  0   .

[ We have ,    ]

Q3.   The value of cosec31° – sec59° is :

  (a)  1     (b)  – 1         (c)  0        (d) 2

Solution:    (c)  0    . 

[ We have ,    ] 

Q4.      

  (a)   – 77        (b)  1       (c)  77       (d)  0

Solution:  (a)   – 77                

  [ We have ,    ]

Q5.  If   , then the value of   is  :

  (a)                (b)            (c)            (d) 

Solution: (a)           

[ We have ,      

  and      

       ]

Q6. If    , then the value of  is

(a) 45°            (b) 30°         (c) 60°           (d) 90°

Solution:  (d)   90°   .

  [ We have ,  

   

  

      ] 

Q7. If   , then the value of  is equal to :

(a)        (b)              (c)        (d)  

Solution:  (c)                               

 [ Given ,     

      ]

Q8. If   , then value of  is equal to –

   (a) 0         (b)           (c)          (d)  

Solution:   (a) 0      .

 [ We have ,   

 

 

  

     ]

Q9. The value of   is :

   (a) 1       (b)  0        (c)          (d)   

Solution:    (b)  0

  [ We have ,

    ]

Q10. Given that   and  , then the value of   is :

  (a) 1         (b) 2      (c) 3        (d) 

Solution:  (a) 1                          

 [ We have ,

 and   

       ] 

Q11.  Which of the following statement  is true ?

 (a)    for all values of   .

   (b)  The value of  increases as  increase .          

  (c)  The value of  increases as  increase .          

 (d)   is not defined for  . 

Solution:   (b)  The value of  increases as  increase .          

Q12. The  value of   is equal to :

  (a)           (b)              (c)       (d)   

Solution:  (c)                       

    [ We have ,  

   

   

    ]

Q13. If  , where  is an acute angle , then the measure of  is :

  (a) 35°       (b) 37°      (c) 39°      (d) 21°

Solution:  (c) 39°                            

 [ We have ,  

  

  ]

Q14. The value of   is :

  (a)  0        (b)  2           (c)  – 2          (d)   1

Solution:   (c)  – 2                            

 [ We have ,  

  ]

Q15. If   , then the value of  is equal to –

  (a)  3          (b)  5          (c)  6            (d)  8

Solution:  (d)  8

[ We have ,   

   ]

Q16. Which of the following statement  is true ?

a) The value of   is always less than 1.   

(b) The value of   is always greater than 1.

(c)    for some angle  .                        

(d)    for some angle  .  

Solution:  (d)     for some angle  .      

 Class 10 Introduction of Trigonometry Fill in the blanks

Q1.  If   , then the value of  is    . 

Solution:   0

[ We have ,    

 

   ]

Q2. If   , then the value of  is equal to   .

Solution:      .

 [ We have ,   

  

 and     

               ]

Q3. If    , then the value of the expression  is  .

Solution:  1 

[  We have ,   

  

 

   

 

      ]

Q4. If   and   , then the value of  is   .

Solution:   30°  

 [ We have ,

 

 

 

   ] 

Q5. If   , then the value of  is   .

Solution:      .

 [ We have ,  

 

      ]

Q6.    is equal to  .

Solution:    – 1

 [  We have ,    ]

Q7. If   , then the value of   is equal to   .

Solution:    1

 [ We have ,

 

  

   

      ]

Q8. If   , then the value of  is equal to  .

Solution:       .

 [  Given ,   

          ]

Q9. If   and   , then the value of  is   .

Solution:  0

 [ We have ,

   ]

Q10. If       , then  equals  

Solution:       .

 [ Given ,       

      and      ]

Q11. The value of    is . 

Solution:   

[ We have ,

   ]

Q12. The value of   is   .

Solution:    1

[ We have ,

   ]

Q12. If  A and 3A – 30° are acute angles such that  , then the value of   is equal to  .

Solution:        .

 [ We have ,  

  

  

  

      ]