If cos(90° − θ) = sin(2θ), what is θ?

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1. Use identity: $\cos(90^\circ-	heta)=\sin	heta$. So the equation becomes $\sin	heta=\sin2	heta$.  
2. Use double-angle: $\sin2	heta=2\sin	heta\cos	heta$. So $\sin	heta=2\sin	heta\cos	heta$.  
3. Factor: $\sin	heta(2\cos	heta-1)=0$. So $\sin	heta=0$ or $\cos	heta=	frac{1}{2}$.  
4. From choices, $\sin	heta=0$ gives $0^\circ,180^\circ$ (not listed). $\cos	heta=	frac{1}{2}$ gives $	heta=60^\circ$. This is option **(a)**.  
FINAL_ANSWER: a

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