Multiple Choice Question (MCQ)
If \sin\theta + \dfrac{1}{\sin\theta } = 0, what is the size of the angle \theta ?

✓
90\degree

×
60\degree

×
\45\degree

×
30\degree
If \sin\theta + \dfrac{1}{\sin\theta } = 0, what is the size of the angle \theta ?
90\degree
60\degree
\45\degree
30\degree
\because \sin\theta + \dfrac{1}{\sin\theta } = 0
\sin^2\theta+1 = 0
\sin\theta =\pm1
\theta =90\degree \text{ or } \theta =270\degree
Therefore A is the correct option