Different coordinates have different equations. list

polar equation

Horizontal direction: r=a( 1-cosθ) or r = a (1+cos θ) (a > 0)

Vertical direction: r=a( 1-sinθ) or r = a (1+sinθ) (a > 0)

Cartesian coordinate equation

The expressions of the plane rectangular coordinate system equation of the heart line are x 2+y 2+a * x = a * sqrt (x 2+y 2) and x 2+y 2-a * x = a * sqrt (x 2+y 2) respectively.

parameter equation

x=a*(2*cos(t)-cos(2*t))

y=a*(2*sin(t)-sin(2*t))