Page 5 - LN
P. 5

2
                                                                      2
                                                                 2
                                                   [since, (a + b)  = a  + 2ab + b ]




                                        [since, sin 2   + cos 2   = 1]















               = 2cosec     = RHS    ( proved)




               Example 6 :Prove that

               Solution:LHS





                =                                           ( Using             )


                       =





                                                                              2
                                                                  3
                                                             3
                                                                                   2
                                                      (using a  - b  = (a - b)(a  + b  + ab))



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