Polar coordinates Flashcards
1
Q
x=
A
rcosu
2
Q
y=
A
rsinu
3
Q
x^2+y^2=
A
r^2
4
Q
u=
A
arctan (y/x)
5
Q
r=a
A
a circle
6
Q
u=??
A
is a half line through 0 making an angle ?? with the initial line
7
Q
r=ua
A
is a spiral starting at 0
8
Q
an egg shape occurs when
A
r=a(p + qcosu)
and p>= 2q
9
Q
a dimple shape occurs when
A
r=a(p + qcosu)
and q=< p < 2q
10
Q
to find a tangent parallel to the initial line
A
set dy/du = 0
11
Q
to find a tangent perpendicular to the initial line
A
set dx/du = 0
