enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Error function - Wikipedia

    en.wikipedia.org/wiki/Error_function

    (), where (2n − 1)!! is the double factorial of (2n − 1), which is the product of all odd numbers up to (2n − 1). This series diverges for every finite x , and its meaning as asymptotic expansion is that for any integer N ≥ 1 one has erfc ⁡ x = e − x 2 x π ∑ n = 0 N − 1 ( − 1 ) n ( 2 n − 1 ) ! !

  3. Natural logarithm - Wikipedia

    en.wikipedia.org/wiki/Natural_logarithm

    For example, ln 7.5 is 2.0149..., because e 2.0149... = 7.5. The natural logarithm of e itself, ln e, is 1, because e 1 = e, while the natural logarithm of 1 is 0, since e 0 = 1. The natural logarithm can be defined for any positive real number a as the area under the curve y = 1/x from 1 to a [4] (with the area being negative when 0 < a < 1 ...

  4. Stirling's approximation - Wikipedia

    en.wikipedia.org/wiki/Stirling's_approximation

    An alternative version uses the fact that the Poisson distribution converges to a normal distribution by the Central Limit Theorem. [5]Since the Poisson distribution with parameter converges to a normal distribution with mean and variance , their density functions will be approximately the same:

  5. Cancelling out - Wikipedia

    en.wikipedia.org/wiki/Cancelling_out

    For example, in the simple equation 3 + 2y = 8y, both sides actually contain 2y (because 8y is the same as 2y + 6y). Therefore, the 2y on both sides can be cancelled out, leaving 3 = 6y, or y = 0.5. This is equivalent to subtracting 2y from both sides. At times, cancelling out can introduce limited changes or extra solutions to an equation.

  6. Euler's constant - Wikipedia

    en.wikipedia.org/wiki/Euler's_constant

    The area of the blue region converges to Euler's constant. Euler's constant (sometimes called the Euler–Mascheroni constant) is a mathematical constant, usually denoted by the lowercase Greek letter gamma (γ), defined as the limiting difference between the harmonic series and the natural logarithm, denoted here by log:

  7. Log-normal distribution - Wikipedia

    en.wikipedia.org/wiki/Log-normal_distribution

    A probability distribution is not uniquely determined by the moments E[X n] = e nμ + ⁠ 1 / 2 ⁠ n 2 σ 2 for n ≥ 1. That is, there exist other distributions with the same set of moments. [4] In fact, there is a whole family of distributions with the same moments as the log-normal distribution. [citation needed]

  8. Propagation of uncertainty - Wikipedia

    en.wikipedia.org/wiki/Propagation_of_uncertainty

    Any non-linear differentiable function, (,), of two variables, and , can be expanded as + +. If we take the variance on both sides and use the formula [11] for the variance of a linear combination of variables ⁡ (+) = ⁡ + ⁡ + ⁡ (,), then we obtain | | + | | +, where is the standard deviation of the function , is the standard deviation of , is the standard deviation of and = is the ...

  9. Chebyshev function - Wikipedia

    en.wikipedia.org/wiki/Chebyshev_function

    The second Chebyshev function can be seen to be related to the first by writing it as = ⁡where k is the unique integer such that p k ≤ x and x < p k + 1.The values of k are given in OEIS: A206722.