Finding intercepts from a table | Algebra I | Khan Academy

TL;DR

The video explains how to find the y-intercept of a linear function by analyzing the x and y values on a graph.

Transcript

The following table of values represents points x comma y on the graph of a linear function. Determine the y-intercept of this graph. So just as a reminder of what the y-intercept even is, if you imagine a linear function or a line if we're graphing it, if we imagine a line, so let's say that is our line right over there. This is our y-axis. This i... Read More

Key Insights

• 😀 The y-intercept is the point of intersection between a linear graph and the y-axis.
• ❣️ The x-intercept is not the same as the y-intercept and represents the point of intersection with the x-axis.
• ❣️ To find the y-intercept, we need to backtrack from the given x values and identify the corresponding y value.
• 💱 The rate of change between x and y remains constant in a linear graph.
• 💱 The change in y for a unit change in x is equal to the slope of the linear graph.
• 🆘 The y-intercept helps determine the starting point or initial value of the linear function.
• 🥘 Graphing the linear function allows visualization of the y-intercept and the overall shape of the graph.

Questions & Answers

Q: What is the y-intercept of a linear graph?

The y-intercept is the point at which the graph intersects the y-axis. In other words, it is the y-coordinate when x equals 0. It helps determine the starting point or initial value of the graph.

Q: How do we find the y-intercept when x equals 0?

To find the y-intercept, we can look for the corresponding y-coordinate in the table of values or calculate it by analyzing the rate of change between x and y. When x equals 0, the y-coordinate represents the y-intercept.

Q: What is the difference between the x-intercept and the y-intercept?

The x-intercept is the point where the graph intersects the x-axis, which means the y-coordinate is 0. On the other hand, the y-intercept is the point of intersection with the y-axis, and the x-coordinate is 0.

Q: How can we determine the y-intercept when only x values are given?

By analyzing the rate of change between x and y, we can determine the y-intercept when x equals 0. If the rate of change remains constant, we can calculate the y-intercept by using the difference between y values for a unit change in x.

Summary & Key Takeaways

• The y-intercept is the point where a linear graph intersects the y-axis.

• The x-intercept is the point where the graph intersects the x-axis, and it is not the same as the y-intercept.

• To find the y-intercept, we can backtrack from the given x values in the table to identify the corresponding y value.