Calculus is a branch of mathematics, developed from algebra, trigonometry, and geometry. Calculus focuses on rates of change (within functions), such as accelerations, curves, and slopes. The development of calculus is credited to Archimedes, Bhaskara, Madhava of Sangamagrama, Gottfried Leibniz and Isaac Newton; lesser credit is given to Isaac Barrow, René Descartes, Pierre de Fermat, Christiaan Huygens, and John Wallis. Fundamental to calculus are derivatives, integrals, and limits.