Trigonometric Equations

Exercises:

1. Solve    = 30, 0

  Solution:  

            Given,  +  3

                            Let   a

 

                                             30

                 +30

                           30+810

                           273 +810

                                       27)3(27)0

                                       27)(

                          Either 27=0    or    30

          When 270

                                            

                     

                                 4a 3 

                                 a 

                                  

                               

          As,   0 <x<π, hence sine cannot be negative

                                          

                                Or

          When,   

                              

                                         

                                          a =

                                        

                                         

          As,   0 <x<π, hence sine cannot be negative

                               

                                   Or     .

                                                    

2. Solve 2

     Solution:

                               We have:  2

   2

            

         Which gives     

                                      

         If we take   

                                 , then         Or    

         Again, if we take  

                                 , then         Or               

         Therefore, the possible solutions of above equations are

                                      ,        where    .

 

3. Solve 

      Solution:

                   We have:  

                   Dividing both sides by 2, we get

                                     

                                               

                                              

                                               

                                                

                                                   Or 

                                       Or  

 

4. Solve: 

Solution:

           We have: 

                 Dividing both sides by 2, we get

                       

                       

                               

                       

                      

                       

                         

 

5. Solve: 

Solution:

      We have: 

                                        

                             

                                                

        Divide the equation by 2

                         

                      

                       

                       

                       

                         

                               

 

6. Find the general solution of the following equation:

     Solution:

       We have 

   

 

                  

                            

                             

                                         

                                         

                                         

         Or   

 

7. Find general solution of the following equation:

          

Solution:

      We have:

                                  

                                   (

 

                                  

                                 

                                             

                                

                                

       As,  so

                                              

                                  

                                  

                               Z

                               Z

 

8. Solve: 

  Solution:

                    We have 

                    

                     

                        [

                    

                      

                      

                        [

                      

                        

                        

                        

                         

                         

                         

                         

                         

                         

 

9. Solve: 

   Solution:

        We have 

                                       

                                       

                           

[

                  

                        

                         

  

                         

                                     

        When