## Trigonometry (11th Edition) Clone

$$\cot\alpha\sin\alpha=\cos\alpha$$
$$A=\cot\alpha\sin\alpha$$ - Quotient Identity: $$\cot\alpha=\frac{\cos\alpha}{\sin\alpha}$$ That makes $A$ into $$A=\frac{\cos\alpha}{\sin\alpha}\times\sin\alpha$$ $$A=\cos\alpha$$