d
1. if n is an odd integer (≠1) and -Π<x<0 . Then the solution of the equation cos nx - sinnx = 1 . is given by
(a) -Î /6 (b) -Î /4 (c) -Î /3 (d) -Î /2
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5 Answers
kamalendu ghosh
·2009-03-17 18:59:34
n is odd...toh ami ektu chorami korlam.... take n=1
so we have cosx- sinx=1
:P
kamalendu ghosh
·2009-03-17 19:22:41
cos^nx -sin ^nx=(cosx-sinx)(**************)
(****************)= always of the form such that if(****************) is =1 then sinx=0 or -Ï€ and cosx=1
but ,,,,,, that is nt possible as -Ï€<x<0
so... only cosx-sinx=1 will gv the solutions..