#### Answer

B

#### Work Step by Step

$\sin \left( x-\dfrac {\pi }{2}\right) =\sin x\cos \dfrac {\pi }{2}-\cos x\sin \dfrac {\pi }{2}=\sin x\times 0-\cos x\times 1=-\cos x\Rightarrow 6\rightarrow B$

Published by
Pearson

ISBN 10:
013421742X

ISBN 13:
978-0-13421-742-0

B

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