Chapter 2: Coordinate Geometry Flashcards
An outline of points on the x and y axis.
What is the length of an interval formula? (also known as Pythagorean theorem)
Length of an interval calculates the exact distance of a line.
a^2 + b^2 = c^2
What is the midpoint of an interval and what is its formula?
The midpoint formula calculates the middle point of a line.
x1+x2/2) , (y1+y2/2) = (x,y) (coordinates
What is the gradient of an interval and what is its formula?
The gradient of an interval is used to calculate the slope of a line. Keep in mind that if the slope is moving downwards, the equation is negative.
rise/run = Gradient
What is ‘the distance formula’ and what is its formula?
The distance formula is an equation used to calculate the length of an individual line.
/(x2-x1)^2 + (y2-y1)^2 = length of an interval (/ = square root)
What is ‘the gradient formula’ and how do you calculate it?
The gradient formula is an alternative way of calculating the gradient of an interval (Pythagorean theorem)
y2-y1/x2-x1 = Gradient
How do you find a parallel line from the formula y = 2x +5
You change the y-intercept, but keep the gradient the same
How do you find the perpendicular line from the formula y = 2x + 5
2*m2 = -1
Therefore parallel line equation = y = -1/2x + y-intercept
What is the general form equation?
ax + by + c = 0
How do you test whether a point lies on a line?
You must substitute the points into y = mx + b form
What is the midpoint of an interval formula?
(x1+x2/2 , y1 + y2/2)
What equation do you use to test whether a point lies on a line?
y = mx + v
Where x is on the Right Hand Side (RHS) and y is on the Left Hand Side (LHS).
How do you find the equation of a line?
- Find the gradient (through any xy coordinates).
- The y-intercept.
- y - mx + b
How do you find the equation of parallel lines?
If m1 = m2, then the line is parallel (in y = mx + b).
How do you find the equation of a perpendicular line?
If m1 * m2 = -1, then the line is parallel (in y = mx + b).
The vertices of a quadrilateral HJKL are H(-8, -5) J(-1, -2) K(2,5) L(-5,2). Find the exact length of the sides of the quadrilateral.
HJ = JK = KL = HL = /58