TI-55 III Programs Part III: Area and Eccentricity of Ellipses, Determinant and Inverse of 2x2 Matrices, Speed of Sound/Principal Frequency TI-55 III Programs Part III:  Area and Eccentricity of Ellipses, Determinant and Inverse of 2x2 Matrices, Speed of Sound/Principal Frequency Reviewed by Anonymous on 20:05 Rating: 5