Presentation on theme: "Identifying a Linear Equation from a Table of Values Slope-Intercept Method."— Presentation transcript:
Identifying a Linear Equation from a Table of Values Slope-Intercept Method
The tasks at hand Identify the slope of a line Identify the intercept of a line Just what is the intercept of a line?
The diagram to the right shows both the X- intercept and the Y-intercept of the linear equation Y = -2X + 4 As you can see, for the relation Y = -2x + 4, the X-intercept is (2, 0) and the Y –intercept is (0, 4).
Y = MX + B To use a table of values, we must calculate both the slope and Y-intercept. To accomplish this, we will always use the Slope-Intercept Formula (Y = MX + B) M stands for the slope. B stands for the Y-intercept. Once we have completed this, we will have the equation. So let’s begin!
Calculating Slope Slope = the change in Y (the rise) as X is increased by 1 (the run) Note the changes in the Y values Increased by 2 every time while the values for X increase by 1 Therefore, slope will be or simply 2. Therefore M = 2. XY
Calculating The Y-Intercept Now select one pair of coordinates. Let’s use (2, 5) for this example We could have chosen any of them Insert this ordered pair and M into Y = MX + B Then solve for B
M = 2 Y = MX + B 5 = (2)(2) + B 5 = 4 + B 5 – 4 = 4 – 4 + B 1 = B So, the equation will be Y = 2X + 1
Another example This time, Y is changing by 3 every time So M = 3 Let’s use (2, 8) Y = MX + B 8 = (3)(2) + B 8 = 6 + B 8 – 6 = 6 – 6 + B 2 = B Y = 3X + 2 XY