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Grade 11IIT JEE Entrance Exam

If tanA and tanB are roots of x^2 - 2x-1=0, then sin^2(A+B) is

Profile image of Laltesh Singh
8 Years agoGrade 11
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1 Answer

Profile image of Arun
6 Years ago
Given,
 
x22x1=0
 
x=21(2)±(2)241(1)
 
x=1+2,x=12
 
tanA=1+2,tanB=12
 
A=tan1(1+2),B=tan1(12)
 
A=6721,B=2221
 
Now,
 
sin2(A+B)
 
=sin2(6721+2221)
 
=sin2(90)
 
=1