[tex]\frac{cot\theta}{csc\theta}=(*)\\------------\\\\cot\theta=\frac{cos\theta}{sin\theta}\\\\csc\theta=\frac{1}{sin\theta}\\------------\\\\(*)=\frac{cos\theta}{sin\theta}:\frac{1}{sin\theta}=\frac{cos\theta}{sin\theta}\cdot\frac{sin\theta}{1}=cos\theta[/tex]
