public function testCrossProductLagrangeFormula(array $A, array $B, array $C)
{
$A = new Vector($A);
$B = new Vector($B);
$C = new Vector($C);
$Ax⟮BxC⟯ = $A->crossProduct($B->crossProduct($C));
$⟮A⋅C⟯B = $B->scalarMultiply($A->dotProduct($C));
$⟮A⋅B⟯C = $C->scalarMultiply($A->dotProduct($B));
$⟮A⋅C⟯B−⟮A⋅B⟯C = $⟮A⋅C⟯B->subtract($⟮A⋅B⟯C);
$this->assertEquals($Ax⟮BxC⟯, $⟮A⋅C⟯B−⟮A⋅B⟯C);
$this->assertEquals($Ax⟮BxC⟯->getVector(), $⟮A⋅C⟯B−⟮A⋅B⟯C->getVector());
}