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#1 2009-08-15 19:29:13

yamini
Member
Registered: 2009-08-10
Posts: 2

trig

please help me solving this question
sinx+siny=3/4  sinx -siny=2/5 then tan(x-y/2)/tan(x+y/2)

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#2 2009-08-15 20:24:45

Identity
Member
Registered: 2007-04-18
Posts: 934

Re: trig

Seeing products of trig terms, the product to sum formula might be useful:

Now, to the other equations,

Adding,

Also, subtracting,

Now if x is in the first quadrant then we get

If x is in the second quadrant then we get

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