04/06/30 21:39
>245
sin(x) + sin(y) + sin(x+y) = 2sin{(x+y)/2}[cos{(x-y)/2} + cos{(x+y)/2}],
-1 + cos{(x+y)/2} ≦ cos{(x-y)/2} + cos{(x+y)/2} ≦ 1 + cos{(x+y)/2}.
-2･sin{(x+y)/4}^2 ≦ cos{(x-y)/2} + cos{(x+y)/2} ≦ 2･cos{(x+y)/4)}^2.
までは出るが．．．
04/06/30 21:39
>245
sin(x) + sin(y) + sin(x+y) = 2sin{(x+y)/2}[cos{(x-y)/2} + cos{(x+y)/2}],
-1 + cos{(x+y)/2} ≦ cos{(x-y)/2} + cos{(x+y)/2} ≦ 1 + cos{(x+y)/2}.
-2･sin{(x+y)/4}^2 ≦ cos{(x-y)/2} + cos{(x+y)/2} ≦ 2･cos{(x+y)/4)}^2.
までは出るが．．．