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Plot the following points:. A(0, 4) B(-3, 0) C(3, 5) D(-8, -11) E(7, -5) F(-3.5, 7.5). Coordinate Geometry. Unit Essential Question: How can you use the coordinate plane to solve problems and demonstrate properties?. The Coordinate Plane. Essential Question:
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Plot the following points: • A(0, 4) • B(-3, 0) • C(3, 5) • D(-8, -11) • E(7, -5) • F(-3.5, 7.5)
Coordinate Geometry Unit Essential Question: How can you use the coordinate plane to solve problems and demonstrate properties?
The Coordinate Plane Essential Question: How do you calculate distance, midpoint, and slope on a coordinate plane?
Origin • x-axis • y-axis • Quadrants • Coordinates • Positive • Negative
Midpoint • What is the midpoint of 7 and 15? • What is the midpoint of (2, 7) and (4, 1)?
Distance? • Mary walks 3 miles north and 2 miles east. Her boyfriend John walks 2 miles south and 4 miles west. What is the straight line distance from their hearts?
Lines in the Plane Essential Question: How do the slopes of parallel and perpendicular lines relate?
Point-Slope form (writing eqs) • Line with slope, m = -2, through (3, -5)
Slope-Intercept Form • y = mx + b • m = • b =
Example: • b(egin) = • m(ove)=
Equations: m = -1/2, (-4, -1) • Point-Slope • Slope Intercept
Example: • x-int (set y=0) • y-int (set x=0)
Transforming to Slope-Intercept • Solve for y: • b(egin) • m(ove)
Example: • b(egin) = • m(ove)=
Writing Equations through 2 pts • (10, 2) & (2, -2) • Step 1: Find Slope • Step 2: Combine pt & slope
Equation through: (7, -4), (-5, 2) • Slope: • Equation:
Horizontal & Vertical Lines • What is special? • Horizontal: • Vertical:
Slopes of Parallel & Perpendicular Lines Essential Question: How do the slopes of parallel and perpendicular lines relate?
Parallel Lines • Are these parallel?
Which is parallel? • Can you write the equation of a 3rd line that is parallel?
Perpendicular Lines • They are OPPOSITE RECIPROCAL slopes.
Writing Perpendicular Equations • Step 1: Perpendicular Slope: • Step 2: Combine Point & Slope:
Perpendicular Lines • Write the equation of the Line through (3, 2), which is perpendicular to 3x + 2y = -6.
Figures in the Plane Essential Question: How can slope, distance and/or midpoint be used to establish properties of a plane figure?
Parallelograms in Quadrilaterals? How should we draw it? • Origin & x-axis.
Coordinate Proofs Essential Question: How can slope, distance and/or midpoint be used to establish properties of a plane figure?
Prove the Opener? • Can we PROVE that the midpoints of a Rhombus form a Rectangle? • Conveniently Plot a Rhombus, then find its midpoints…
PROVE Triangle Midsegment Theorem. • Midsegment is Parallel to Base and ½ the length of the 3rd side! • Place Triangle. Find Midpoints, calculate slope and length of Midsegment.