Parametric Equations Flashcards
Cartesian equations describe
Graphs in x,y plane
They are single equation linking x and y
Parametric equation
Two linked equations used for more complex graphs
X and y defined separately in terms of third variable called parameter
T or circle with line in middle
Sketching parametric graph
Choose t values use table of coordinates and plot x,y coor
Finding parameter of x and y
Given variable to substitute
EASY
Circle can be given by parametric equations.
X = r cos t + a
Y = r sin t + b
Centre (a,b)
Radius r
Use parametric equations to find where graphs intersect.
When two ts give the same coordinate that’s when the line crosses over itself.
Sub parametric equations into line equation.
Rearrange factorise to find t values
Go back to parametric and use t values to find x and y coordinates.