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Grade 11Trigonometry

sove for x
sin3y = 4 siny * sin(x+y) *sin(x-y) where y is not equal to npi

Profile image of G.VENKATESH
10 Years agoGrade 11
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2 Answers

Profile image of Nicho priyatham
ApprovedApproved Tutor Answer10 Years ago
sin3y = 4 siny * sin(x+y) *sin(x-y)
 sin(x+y) *sin(x-y)=sin2 x-sin2 y
so sin3y= 4siny(sin2 x-sin2 y)
3siny-4sin3y=4sinysin2x-4sin3y
so sin2x=3/4
x=npie+ pie/3
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Profile image of raj
10 Years ago
hello, 
sin3y = 4 siny * sin(x+y) *sin(x-y)
 sin(x+y) *sin(x-y)=sin2 x-sin2 y
so sin3y= 4siny(sin2 x-sin2 y)
3siny-4sin3y=4sinysin2x-4sin3y
so sin2x=3/4
x=npie+ pie/3