2.0 Co-ordinate Geometry Flashcards
What are co-ordinate?
A means of describing a position relative to some fixed point.
In the Cartesian System (named after Rene Descartes)..
..position is given in perpendicular directions, x, y in two dimension; x, y, z in three dimensions.
What does ‘plot’ mean?
(a line or curve) To mark the points and join them up as accurately as you can.
What does ‘sketch’ mean?
To mark points in approximately the right positions and join them up in the right general shape.
What does ‘draw’ mean?
To use a level of accuracy appropriate to the given circumstances, this could be anything between a rough sketch and a very accurately plotted graph.
What is a ‘line’ in mathematics?
It is usually understood to mean a straight line.
What is the gradient of a line?
The slope of the line.
m = Δy/Δx
Parallel lines = ?
m1 = m2
Perpendicular lines = ?
(m1) x m(2) = -1
What is the length of a line?
√(X2-X1)² + (Y2 - Y1)²
What is the midpoint of a line joining two points?
[ (X1 + X2)/2 ; (Y1 + Y2)/2 ]
What is the equation of a straight line?
y = mx + c
