MCQ
$\sin (\pi + \theta )\sin (\pi - \theta )\,{\rm{ cose}}{{\rm{c}}^2}\theta = $
  • A
    $1$
  • $-1$
  • C
    $\sin \theta $
  • D
    $ - \sin \theta $

Answer

Correct option: B.
$-1$
b
(b) $\sin (\pi + \theta )\sin (\pi - \theta ){\rm{cose}}{{\rm{c}}^2}\theta $

$ = - \sin \theta \sin \theta \frac{1}{{{{\sin }^2}\theta }} = - 1$.

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