Scientific calculator

This is an expression calculator, not a button-sequence one: you write the whole calculation the way you would on paper and it is parsed with correct precedence. Multiplication binds tighter than addition, exponentiation is right-associative (2^3^2 is 512, not 64), and unary minus binds looser than a power, so −2² is −4.

What it understands

• Implicit multiplication — 2(3+4) and 3sin(0) work.
• Bare function calls — sqrt 81 and √81 need no parentheses.
• Percent literals — 50% * 80 is 40, while 10 % 3 is a modulo.
• Factorials — 5!, extended to non-integers via the gamma function.
• Constants — pi, e, tau, phi.

Functions available: abs, acos, acosh, asin, asinh, atan, atan2, atanh, cbrt, ceil, cos, cosh, deg, exp, fact, floor, gamma, gcd, hypot, ln, log, log10, log2, max, min, mod, pow, rad, round, sign, sin, sinh, sqrt, tan, tanh, trunc.

Radians

Trigonometric functions take radians, as they do in every programming language and in calculus. Use rad(30) to convert degrees on the way in, and deg(x) to convert back out — so the sine of 30 degrees is sin(rad(30)).

Precision

Arithmetic uses IEEE-754 double precision, the same as every browser and spreadsheet. Results are shown to 14 significant figures, which hides the usual floating-point noise — but it is still there underneath, which is why 0.1 + 0.2 is famously not exactly 0.3.