Asked by Kramer
                sin(5x)/sin(4x) = ?
How do I cancel them out to get a constant?
            
        How do I cancel them out to get a constant?
Answers
                    Answered by
            bobpursley
            
    sin(5x)=sin(4x+x)=2sin4xsinx
    
                    Answered by
            Kramer
            
    what property is this? in terms of a and b?
    
                    Answered by
            Reiny
            
    not true Bob,
sin(4x+x)sin4x = (sin4xcosx + cos4xsinx)sin4x
= cosx + cos4xsinx/sin4x
now sin4x = sin(3x+x) = sin3xcosx + cos3xsinx
and cos4x = cos3xcosx - sin3xsinx)
now in your list of trig expansions you might have seen:
sin3x = 3sinx - 4sin^3 x
cos3x = 4cos^3 x - 3cosx
now if you have the patience to plug all that back into the above, you will have a great mess
but all expressed in x.
Don't really know what you wanted here.
    
sin(4x+x)sin4x = (sin4xcosx + cos4xsinx)sin4x
= cosx + cos4xsinx/sin4x
now sin4x = sin(3x+x) = sin3xcosx + cos3xsinx
and cos4x = cos3xcosx - sin3xsinx)
now in your list of trig expansions you might have seen:
sin3x = 3sinx - 4sin^3 x
cos3x = 4cos^3 x - 3cosx
now if you have the patience to plug all that back into the above, you will have a great mess
but all expressed in x.
Don't really know what you wanted here.
                    Answered by
            Reiny
            
    sin(4x+x)sin4x = (sin4xcosx + cos4xsinx)sin4x 
should have been:
sin(4x+x) / sin4x = (sin4xcosx + cos4xsinx) / sin4x
    
should have been:
sin(4x+x) / sin4x = (sin4xcosx + cos4xsinx) / sin4x
                                                    There are no AI answers yet. The ability to request AI answers is coming soon!
                                            
                Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.