2006-11-27 01:45:37 · 8 answers · asked by satyashankar v 1 in Science & Mathematics ➔ Mathematics
sin(pi/7)*sin(2pi/7)*sin(3pi/7)
sin (pi/7) = sin (0.45 radians) =.4350
sin (2pi/7)= sin(.88 radians) =.771
sin(3pi/7)=sin(1.35 radians) = .976
Thus the abswer is .435*.771*.976=.327
2006-11-27 02:13:13 · answer #1 · answered by ironduke8159 7 · 0⤊ 2⤋
=
sin(pi/7) x sin(2pi/7) x sin(pi/7 + 2pi/7)
for sin(2pi/7), use the double angle formula
for sin(pi/7 + 2pi/7), use sine of a sum
just a starting point
2006-11-27 01:50:14 · answer #2 · answered by RolloverResistance 5 · 0⤊ 0⤋
convert add x operation to + between sin{pi/7} X sin{3pi/7}.
multiply result in sin{2pi/7}.
do this work again for result.
2006-11-27 02:01:13 · answer #3 · answered by Mr.ENG 2 · 0⤊ 0⤋
using sin A sin B = 1/2(cos (A-B)/2 - cos (A+B)/2)
sin pi/7 sin 3pi/7 = 1/2(cos pi/7 - cos 2pi/7)
so given expression = 1/2(cos pi/7- cos 2pi/7) sin pi/7
= 1/2(cos pi/7 sin pi/7- sin pi/7 cos 2pi/7)
= 1/4( sin 2pi/7 - sin pi/7 cos 2pi/7)
2006-11-27 22:01:54 · answer #4 · answered by Mein Hoon Na 7 · 0⤊ 1⤋
Use the product formulas
sin u sin v = [cos(u - v) - cos(u + v)]/2 and
cos u sin v = [sin(u + v) - sin(u - v)]/2
to get
[sin(2pi/7) + sin(4pi/7) - sin(6pi/7)]/4 = 0.330719
2006-11-27 02:05:43 · answer #5 · answered by airtime 3 · 0⤊ 0⤋
open the 11th stndrd rd sharma n u wil gt d formula 4 d ques else go to mathwolrd.wolfram.com n search 4 trigonometry
2006-11-27 01:53:27 · answer #6 · answered by mundane gal 2 · 0⤊ 0⤋
In radians it is approximatly:
.33071891388307
2006-11-27 01:50:55 · answer #7 · answered by bartathalon 3 · 0⤊ 0⤋
0.000002883
2006-11-27 03:00:34 · answer #8 · answered by watch812 1 · 0⤊ 1⤋
omg...yuck
2006-11-27 01:54:15 · answer #9 · answered by Anonymous · 0⤊ 0⤋