Cot Identity Aa8164
1. We are asked to show that $$\frac{\cot^2 \alpha}{\csc \alpha - 1} = \csc \alpha + 1$$.
2. Recall the identities:
- $$\cot^2 \alpha = \csc^2 \alpha - 1$$
- $$\csc \alpha = \frac{1}{\sin \alpha}$$
3. Substitute $$\cot^2 \alpha$$ in the left-hand side (LHS):
$$\frac{\cot^2 \alpha}{\csc \alpha - 1} = \frac{\csc^2 \alpha - 1}{\csc \alpha - 1}$$
4. Factor the numerator as a difference of squares:
$$\csc^2 \alpha - 1 = (\csc \alpha - 1)(\csc \alpha + 1)$$
5. Substitute back:
$$\frac{(\csc \alpha - 1)(\csc \alpha + 1)}{\csc \alpha - 1}$$
6. Cancel the common factor $$\csc \alpha - 1$$ (assuming $$\csc \alpha \neq 1$$):
$$\csc \alpha + 1$$
7. This matches the right-hand side (RHS), so the identity is proven.
Final answer:
$$\frac{\cot^2 \alpha}{\csc \alpha - 1} = \csc \alpha + 1$$