Question

What is notation for the Second Derivative?

Answer 1

If you prefer Leibniz notation, second derivative is denoted `(d^2y)/(dx^2)`.

Example:

`y = x^2`

`dy/dx = 2x`

`(d^2y)/(dx^2) = 2`

If you like the primes notation, then second derivative is denoted with two prime marks, as opposed to the one mark with first derivatives:

`y = x^2`
`y' = 2x`
`y'' = 2`

Similarly, if the function is in function notation:

`f(x) = x^2`
`f'(x) = 2x`
`f''(x) = 2`

Most people are familiar with both notations, so it doesn't usually matter which notation you choose, so long as people can understand what you're writing. I myself prefer the Leibniz notation, because otherwise I tend to confuse the apostrophes with exponents of one or eleven. Though the primes notation is more shorthand and quicker to write, so many people prefer it.