Coordinate Systems Flashcards
Polar axis
X-axis in the coordinate system
The radial coordinate (r)
The distance from the origin
Angular coordinate (θ)
The angle measure from the polar axis to the radial coordinate
Calculate ‘x’ from ‘r’ and θ
x=r*cos(θ)
Calculate ‘y’ from ‘r’ and θ
y=r*sin(θ)
Calculate ‘r’ from ‘x’ and θ
r=x/(cos θ)
Calculate ‘r’ from ‘y’ and θ
r=y/(sin θ)
Calculate ‘r’ from ‘x’ and ‘y’
r=√(x^2+y^2)
Calculate ‘x’ from ‘r’ and ‘y’
x=√(r^2-y^2)
Calculate ‘y’ from ‘x’ and ‘r’
y=√(r^2-x^2)
Calculate θ from ‘y’ and ‘x’
θ=tan^(-1)(y/x)
Calculate θ from ‘y’ and ‘r’
θ=sin^-1(y/r)
Calculate θ from ‘x’ and ‘r’
θ=cos^-1(x/r)
Calculate ‘x’ from ‘y’ and θ
x=y/tanθ
Calculate ‘y’ from ‘x’ and ‘θ’
y=x*tanθ
Cardioid
Graph of the radius with a change in θ
Lemniscate
Graph of the (radius)^2 with a change in θ
Cartesian Coordinates in a Plane
Describe the location of a point in terms of (x,y)
Polar Coordinates
Describe the location of a point in terms of (r,θ)
Slope of a tangent line in polar coordinates
mTan=[f’(θ)sinθ+f(θ)cosθ]/[f’(θ)cos-f(θ)sinθ]
Using polar coordinates to approximate integrals
∫1/2*(f(θ)^2-g(θ)^2)dθ
On the interval from [θi,θf]
See pg 660
Cartesian coordinates for horizontal ellipses
1=(x^2/a^2)+(y^2/b^2)
b- √(a^2-c^2)
a- vertices at (0,±a) or (±a,0)
c- foci at (0,±c) or (±c,0)
Cartesian coordinates for vertical ellipses
1=(y^2/a^2)+(x^2/b^2)
b- √(a^2-c^2)
a- vertices at (0,±a) or (±a,0)
c- foci at (0,±c) or (±c,0)
Cartesian coordinates for horizontal hyperbolas
1=(x^2/a^2)-(y^2/b^2)
b- √(c^2-a^2)
a- vertices at (0,±a) or (±a,0)
c- foci at (0,±c) or (±c,0)