Acute triangle, Trigonometric function! (Posted on 2007-10-13)

	Submitted by Chesca Ciprian
Rating: 4.0000 (1 votes)
Solution:	(Hide)
From the graph of the sin(x) function between 0 and PI/2 if we take 3 points A(x, sin(x)), origin and (PI/2,1) there will take shape 1 triangle and otherwise 1 triangle and 1 trapezium. If we consider that the area of the first triangle is smaller then the sum of the second triangle and the trapezium we will find the relation (well know!!!) sin(x)>=2*x/PI. After we replace in this relation the angle A,B, and C and sum this 3 relation we will find sin(A) + sin(B) + sin(C) > 2

	Subject	Author	Date
	Solution	Bractals	2007-10-15 05:41:03
	re(2): Solution	K Sengupta	2007-10-14 10:59:29
	re: proof (maybe)	Charlie	2007-10-14 10:39:37
	re: Solution	Charlie	2007-10-14 10:37:43
	Solution	K Sengupta	2007-10-14 06:08:14
	proof (maybe)	Daniel	2007-10-14 05:32:49
	Hint	Bractals	2007-10-13 19:41:08
	re: not a proof but ...	Charlie	2007-10-13 16:47:30
	not a proof but ...	Charlie	2007-10-13 16:39:03