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Trigonometric Inequalities (Posted on 2008-06-06) Difficulty: 3 of 5
Let s,R and r be the semi-perimeter, Circumradius and Inradius of triangle ABC respectively. Then show that:

1) 8r2(cos(A-B)+cos(B-C)+cos(C-A)) ≤ s2-3r2

2) (1/(sinA*sinB))+(1/(sinB*sinC))+(1/(sinC*sinA)) ≥ 4

See The Solution Submitted by Praneeth    
Rating: 4.0000 (2 votes)

Comments: ( You must be logged in to post comments.)
  Subject Author Date
SolutionTrigonometric with some algebra!Chesca Ciprian2008-06-15 03:58:10
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