Answer: The first option.
Step-by-step explanation:
1. To solve this exercise you need to remember that:
- An even function is a function with the following property:
f(-x)=f(x)
- An odd function is a function with this property:
f(-x)=-f(x)
2. By definition, the contangent is an odd function, therefore you have that:
cot(-θ)=-cot(θ)
Then:
3. So, you can coclude that the first step is wrong. Therefore, the answer is the first option.