Writing an Equation in Point-Slope Form (3.10.3) Flashcards
• The point-slope form of an equation: y – y1 = m(x – x1). This equation is created from the slope formula. It allows you to create the equation of a line knowing any one point and the slope.
• The point-slope form of an equation: y – y1 = m(x – x1). This equation is created from the slope formula. It allows you to create the equation of a line knowing any one point and the slope.
Again, you are substituting values into the general equation.
Your slope is –1/4. Substitute –1/4 for m.
Your point is (–1,3). Substitute its values in for x1
and y1.
This formula is valuable if you are given the slope and any one point on a line.
Notice: The signs change as the point values go into the
formula. They are subtracting.
You’ve got your equation. You’re done.
Thinking in reverse, you can look at an equation and discern the details needed to be able to graph a line.
Looking at this equation, you know immediately that the
slope, m, is 2/3.
You also know that one point on the line is located at
(–1,2).
Remember: change the signs on the numbers from the
equation to determine the x- and y-values for the point.
Place the one point you know, (–1,2).
From there count up 2 and to the right 3 to locate the second point.
Draw the line through the two points.
You’ve got your unique line.
Again, you are substituting values into the general equation.
Your slope is –1/4. Substitute –1/4 for m.
Your point is (–1,3). Substitute its values in for x1
and y1.
This formula is valuable if you are given the slope and any one point on a line.
Notice: The signs change as the point values go into the
formula. They are subtracting.
You’ve got your equation. You’re done.
Thinking in reverse, you can look at an equation and discern the details needed to be able to graph a line.
Looking at this equation, you know immediately that the
slope, m, is 2/3.
You also know that one point on the line is located at
(–1,2).
Remember: change the signs on the numbers from the
equation to determine the x- and y-values for the point.
Place the one point you know, (–1,2).
From there count up 2 and to the right 3 to locate the second point.
Draw the line through the two points.
You’ve got your unique line
