Final answer:
The slope of a tangent line to a curve can indicate the direction and steepness of the curve at a specific point. A positive slope indicates that the curve is increasing, a negative slope indicates that it is decreasing, and a slope of zero indicates that it is horizontal.
Step-by-step explanation:
The slope of a tangent line to a curve can indicate the direction and steepness of the curve at a specific point. A positive slope indicates that the curve is increasing, moving up the y-axis as the x-value increases. A negative slope indicates that the curve is decreasing, moving down the y-axis. A slope of zero indicates that the curve is horizontal, neither increasing nor decreasing.