GOAL: To understand and graph intercepts of linear equations
The graph of any linear equation, Ax+By=C, is a line.
Two points are all that are needed to determine a line.
Two points that are convenient to use are the x-intercept and the y-intercept.
Consider the line given by the equation Ax+By=C
1. The x-intercept of the line is the value of x when y=0.
To find the x-intercept, let y=0 and solve for x in Ax+By=C
2. The y-intercept of the line is the value of y when x=o.
To find the y-intercept, let x=0 and solve for y in Ax+By=C
What is the x-intercept of the line given by Ax+By=C?
What is the y-intercept of the line given by Ax+By=C?
Use the graph to answer the following questions:
What is the x-intercept?
What is the y-intercept?
Check your solutions algebraically.
Use the graph to answer the following questions:
What is the x-intercept?
What is the y-intercept?
Check your solutions algebraically.
EXTENSIONS: (Check your answers using graphing calculator)
1. What is the x-intercept of the line given by x=a?
What is the y-intercept?
2. What is the y-intercept of the horizontal line passing through the point (a,b)?
What is the x-intercept?
3. What is the x-intercept of the line given by y=-x?
What is the y-intercept?
Are they the same point or different points?