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Hey!___96 points___plss plsss solve it........... ​

Answer»

Step-by-step explanation:

Taking LHS :

\frac{ \sin(2x) -  \sin(3x) +  \sin(4x)   }{ \<klux>COS</klux>(2x)  -  \cos(3x)  +  \cos(4x) }

[note that:

\frac{2x + 4x}{2}  = 3x

=  >  \frac{( \sin(2x )+ \sin(4x)   -  \sin(3x) ) }{( \cos(2x) +  \cos(4x)  -  \cos(3x)  }

ALSO we know that:

sin(A+B) = 2sin((A+B)/2)cos((A-B)/2)

=>cos(A+B) = 2 cos((A+B) /2)cos(A-B)/2)

=  >  \frac{2 \sin( \frac{2x + 4x}{2}  ) \times  \cos( \frac{2x - 4x}{2} )  -  \sin(3x)  }{2 \cos( \frac{2x + 4x}{2} )  \times  \cos( \frac{2x - 4x}{2} )  -  \cos(3x) }

=  >  \frac{2 \sin(3x) \times  \cos( - x)   -  \sin(3x) }{2 \cos(3x) \times  \cos( - x) -  \cos(3x)   }

=  >  \frac{ \sin(3x))(2 \cos(x) - 1))  }{ \cos(3x)((2 \cos(x) - 1 )) }

Now the same term will cancel out THEREFORE :

=  >  \frac{ \sin(3x) }{ \cos(3x) }

=> TAN3X = RHS

Hence proved!

HOPE IT HELPS YOU



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