Final answer:
The value of tan(-π/4) is -1; this result can be found by considering the sine and cosine values at this angle, which both give √2/2, and thus their quotient is -1.
Step-by-step explanation:
The question asks for the value of the tangent function at a specific angle, specifically tan(-π/4). In mathematics, particularly trigonometry, this value is well-known. The tangent of an angle in the unit circle corresponding to -π/4, which is the same as 7π/4, is -1. This comes from the property that tan(θ) equals sin(θ)/cos(θ), and at the angle -π/4, both the sine and cosine values are √2/2, resulting in a tangent value of -1.