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Trigonometry

for the smallest positive values of x and y the equation 2(sinx+sin y)-2cos(x-y)=3
(a)sinx+y/2=1
(b)cos(x-y/2)=1/2
(c)number ofordered pairs (x,y)is2
(d) number of orderd pairs(x,y)is3

Profile image of param
11 Years agoGrade
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1 Answer

Profile image of Nishant Vora
11 Years ago
Hello Student,

2(sinx+sin y)-2cos(x-y)=3
use this formula
SinC + SinD = 2Sin[(C+D)/2]Cos[(C-D)/2]

2(Sin[(x+y)/2]Cos[(x-y)/2])-2[2cos2[(x-y)/2] – 1}=3
take cos common and then simplify it further