T991 Scientific Calculator is the calculator for students and engineering student. Emulates CASIO fx-991es physical calculator. Features: 1.percentage, powers, roots, trigonometric, logarithms calculator. 2.linear algebra, calculus, complex numbers, display result in rectangular and polar coordinates, matrix and vector. 3.equation solver can solve quadratic, cubic equations, systems of equations. 4.support undo, history, copy/paste Random integers Fraction calculations Combination and permutation Statistics (List-based STAT data editor, standard deviation, regression analysis) 9 variables Table function Equation calculations Integration/differential calculations Matrix calculations Vector calculations Complex number calculations CALC function SOLVE function Base-n calculation