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sin(x+pi/6)-sin(x-pi/6)=1/2

2007-12-27 18:52:56 · 4 answers · asked by Anonymous in Science & Mathematics Mathematics

4 answers

LHS
sin x cos π/6 + cos x sin π/6
sin x cos π/6 - cos x sin π/6
Subtracting gives:-
2 cos x sin π/6 = cos x

cos x = 1/2
x = π/3 , 5π/3

2007-12-28 01:57:51 · answer #1 · answered by Como 7 · 3 0

using factor formula,
sin(x+pi/6)-sin(x-pi/6)=1/2
2cos x sin(pi/3)=1/2
(2cos x)(3^(1/2))/2=1/2
2cos x=1/(3^(1/2))
cos x=1/(2)(3^(1/2))
x=73.22,286.88 in degrees and x is in the interval [0,360].

2007-12-27 19:15:13 · answer #2 · answered by William 3 · 0 0

sin(x+pi/6)-sin(x-pi/6)=1/2
[sinx cos(pi/6) + sin(pi/6)cosx] - [sinx cos(pi/6) - sin(pi/6)cosx]=1/2

sinx cos(pi/6) + sin(pi/6)cosx - sinx cos(pi/6) + sin(pi/6)cosx =1/2

2 . sin(pi/6)cosx =1/2
2 * 0.5 cosx =1/2
cosx =1/2
x = pi/3 . . . or . . . x = (5/3) pi

Alejandra

2007-12-31 12:55:37 · answer #3 · answered by ale_23 7 · 0 0

sin(x + (pi/6)) = sin(x)cos(pi/6) + sin(pi/6)cos(x)
sin(x - (pi/6)) = sin(x)cos(pi/6) - sin(pi/6)cos(x)

sin(x + (pi/6)) - sin(x - (pi/6)) =

(sin(x)cos(pi/6) + sin(pi/6)cos(x)) - (sin(x)cos(pi/6) - sin(pi/6)cos(x))

sin(x)cos(pi/6) + sin(pi/6)cos(x) - sin(x)cos(pi/6) + sin(pi/6)cos(x)

sin(pi/6)cos(x) + sin(pi/6)cos(x)

2(sin(pi/6)cos(x))
2((1/2)cos(x))
cos(x)

so

cos(x) = (1/2)
x = pi/3 and 5pi/3

2007-12-27 22:17:23 · answer #4 · answered by Sherman81 6 · 0 1

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