A scientific calculator usually has special buttons for parentheses, trigonometric functions, exponents, inverses and pi -- among other things. A graphing calculator does even more.

Starting this spring, pupils in 14 US states will be able to use the TI-like Desmos online calculator during standardized testing run by the Smarter Balanced consortium.

H. E. White, Jr., Functions with a Concave Modulus of Continuity, Proceedings of the American Mathematical Society, Vol. 42, No. 1 (Jan., 1974), pp. 104-112 ...