Coordinate Geometry
Theorem 11.2 The Equation of a Circle.
The equation of a circle with its center at (a,b) and a radius r is:
r²= (x - a)² + (y - b)²
Slope of a line:
Theorem:
If the slope of two lines are equal then the line are parallel.
Theorem:
If the product of the slopes of two non-vertical lines is -1 then the
lines are perpendicular.
Theorem: The Standard Equation of a Line.
Any equation that can be written as ax + by = c, where a and b are
nonzero numbers, is a line.
Theorem: Point-Slope Form
The equation of a line with point and slope m is:
y -y1 = m(x - x1)
Theorem: The Slope-Intercept Form
The equation of a line with slope m and y-intercept b is:
y = mx + b