Slopes and Tangent Lines


In Exercises 1–4, use the grid and a straight edge to make a rough estimate of the slope of the curve (in y-units per x-unit) at the points P₁ and P₂.

Verified step by step guidance

1. Identify the points P₁ and P₂ on the graph. P₁ is located at approximately (0.5, 1) and P₂ is at approximately (2, 1.5).
2. To estimate the slope at P₁, draw a tangent line at this point. A tangent line is a straight line that touches the curve at exactly one point and represents the instantaneous rate of change at that point.
3. Determine the slope of the tangent line at P₁. The slope is calculated as the change in y divided by the change in x (rise over run). Use the grid to estimate these changes.
4. Repeat the process for point P₂. Draw a tangent line at P₂ and estimate its slope using the grid.
5. Compare the slopes at P₁ and P₂ to understand how the rate of change of the curve varies between these two points.

Key Concepts

Slope of a Curve

The slope of a curve at a given point represents the rate of change of the function at that point. It is calculated as the ratio of the change in the y-coordinate to the change in the x-coordinate (rise over run) as you approach the point. For curves, this is often approximated using secant lines between two points, which can give insight into the behavior of the curve.

Tangent Line

A tangent line to a curve at a specific point is a straight line that just touches the curve at that point, representing the instantaneous rate of change of the function. The slope of the tangent line is equal to the derivative of the function at that point. This concept is crucial for understanding how functions behave locally around specific points.

Estimating Slopes

Estimating slopes involves using graphical methods to approximate the slope of a curve at specific points. This can be done by drawing a tangent line at the point of interest and measuring its steepness. In the context of the given question, students are asked to visually assess the slope at points P₁ and P₂ using a grid, which helps develop intuition about derivatives and rates of change.