To solve the question, let's analyze the trigonometric identity involved and determine the correct reasoning for the given options.

The question involves determining the result of a trigonometric identity using the given options. Let's understand the identity first.

Trigonometric Identity Explanation

We consider the identity related to the tangent function, which often involves transformations based on angles or specific trigonometric rules.

One common trigonometric identity is for the tangent of supplementary angles:

\tan(180^\circ - \theta) = -\tan\theta

This formula states that the tangent of an angle subtracted from 180 degrees is the negative of the tangent of the original angle.

Step-by-Step Solution

1. Consider the identity for angle transformation: \tan(180^\circ - \theta) = -\tan\theta .
2. Apply this identity as it directly indicates the transformation of tangent values via the supplementary angle.
3. This identity clearly shows that the result of this transformation gives a negative tangent of the original angle.

Justification of the Correct Answer

Based on the trigonometric identity mentioned, the transformation results in -\tan\theta . Thus, the correct answer option is <p>−1</p>, meaning the expression equals -1 under the specific condition set by the given trigonometric transformation.

The result of -\tan{\theta} correctly corresponds to the answer indicating -1 as per the question context.

Conclusion

Using the appropriate trigonometric identities allows determining the correct relationship or transformation for tangent values. Here, through the identity \tan(180^\circ - \theta) = -\tan\theta , we conclude that the transformation produces the correct answer as -1. Hence, the correct answer is −1.