The Quarterly Journal of Pure and Applied Mathematics, Volume 8

a₁ ABCD angles angular axes axis B₁ Blissard centre chord circle coefficients condition conic conjugate constant corresponding curve of section denote determinant differential equation displacement ellipse equal expression foci formula four function Geometry given point Hence hyperbola identical infinite integral line of curvature linear locus nine-point circle normals obtain orthogonal orthogonal matrix P₁ P₂ pair parabola passing perpendicular plane at infinity points at infinity points of intersection polar principal plane quadric reciprocal represented respectively result satisfied sides skew sphere spherical straight line substitution surface tangential coordinates tangential equation tangents theorem touch triads triangle of reference trilinear coordinates values vanish variables whence Σ Σ Στ аф