I'm with Gauss here

"sin2θ is odious to me, even though Laplace made use of it; should it be feared that might become ambiguous, which would perhaps never occur... well then, let us write (sin θ)2, but not sin2θ, which by analogy should signify sin(sin θ)." -- Gauss-Schumacher correspondence, quoted in Eli Maor, Trigonometric Delights.

This must be one of the worst notational choices in mathematics.


  1. Agreed. Yet another example of the evils that follow from mathematicians' laziness about writing parentheses.

    1. They aren't going to help if we are only interested in pure functions. If someone wants the derivative of Sin^2, parentheses won't resolve the ambiguity that is the root of the problem.

    2. Writing sin^2 is way worse than writing sin^2 x.