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2sin^2x = sinx + 1; 0<or=x<or=2pi?
please help me I need to finish this before school starts and I dont' know how to do it.
3 Answers
- 8 years agoFavorite Answer
Here 2 sin ² x = sin x + 1
2 sin ² x - sin x - 1 = 0.
(2 sin x + 1)(sin x - 1) = 0
2 sin x + 1 = 0 AND sin x - 1 =0
so
sin x = -1/2 and sin x = 1
so
x = π/2 (in case of sin x = 1)
and
x= 7π/6, 11π/6 (or you can write it as - π/6 .) [ in case of sin x = -1/2]
- Engr. RonaldLv 78 years ago
2sin^2x = sinx + 1
2sin^2(x) - sin(x) - 1 = 0
[2sin(x) + 1][sin(x) - 1] = 0
2sin(x) + 1 = 0, sin(x) - 1 =0
2sin(x) = - 1, sin(x) = 1
sin(x) = - 1/2
x = - Ï/6. 7Ï/6, Ï/2, answer//