X = X ( θ ) = X porque θ - y pecado θ {\ Displaystyle \ mathbf {x} = \ mathbf {x} (\ theta) = x \ cos \ theta -y \ sin \ theta}
y = y ( θ ) = X pecado θ + y porque θ {\ Displaystyle \ mathbf {y} = \ mathbf {y} (\ theta) = x \ sin \ theta + y \ cos \ theta}
X = X θ ( t ) = a porque t porque θ - B pecado t pecado θ {\ Displaystyle \ mathbf {x} = \ mathbf {x} _ {\ theta} (t) = a \ cos \ t \ cos \ theta -b \ sin \ t \ sin \ theta}
y = y θ ( t ) = a porque t pecado θ + B pecado t porque θ {\ Displaystyle \ mathbf {y} = \ mathbf {y} _ {\ theta} (t) = a \ cos \ t \ sin \ theta + b \ sin \ t \ cos \ theta}
X 2 a 2 + y 2 B 2 = 1. {\ displaystyle {\ frac {\ mathbf {x} ^ {2}} {a ^ {2}}} + {\ frac {\ mathbf {y} ^ {2}} {b ^ {2}}} = 1 .}
( X porque θ - y pecado θ ) 2 a 2 + ( X pecado θ + y porque θ ) 2 B 2 = 1 {\ Displaystyle {\ dfrac {(x \ cos \ theta -y \ sin \ theta) ^ {2}} {a ^ {2}}} + {\ dfrac {(x \ sin \ theta + y \ cos \ theta ) ^ {2}} {b ^ {2}}} = 1}