If `xsina+ysin2a+zsin3a=sin4a` `xsinb+ysin2b+zsin3b=sin4b`, `xsinc+ysin2c+zsin3c=sin4c`, then the roots of the equation `t^3-(z/2)t^2-((y+2)/4)t+((z-x)/8)=0,a , b , c ,!=npi,` are (a)`sina ,sinb ,sinc` (b) `cosa ,cosb ,cosc` (b)`sin2a ,sin2b ,sin2c` (d) `cos2a ,cos2bcos2c`

Explanation

`xsina+ysin2a+2sin3a=sin4a`

`xsina+y(2sinacosa)+2(3sina-4sin3a)=2sin2acos2a`

`xsina+2ysinacosa+sina2(3-4sin^2a)=4sinacosacos2a`

`a+2ycosa+2(3-4sin^2a)=4cosacos2a`

`8cos^3a-4zcos^2a-(2y+4)cosa+(z-x)=0`

`cos^3a-(z/2)cos^a-((y+2)/4)cosa+((z-x)/8)=0`

`t=cosa`

`t^3-(z/2)t^2-((y+z)/4)t+((z-x)/8)=0`

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