If sin θ = -1/2 for 0 < θ < 360, the value of θ is

  • A 30° and 150°
  • B 150° and 210°
  • C 210° and 330°
  • D 150° and 330°
jamb 2005mathematics

The correct answer is C. 210° and 330°

The sine function is negative in the third and fourth quadrants. Since the reference angle for sin(θ) = 1/2 is 30°, the angles that satisfy the equation sin(θ) = -1/2 in the interval 0 < θ < 360 are 180 + 30 = 210° and 360 - 30 = 330°.

Therefore, the value of θ is 210° and 330°

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