.. probability lecture Helpful math ============= Properties of exponentials ------------------------------ +--------------------------------------+ | :math:`a^{-n} = \frac{1}{a^{n}}` | +--------------------------------------+ >>> a,n = 2,3 >>> print(a**(-n),1.0/a**n) 0.125 0.125 +-------------------------------------+ | :math:`a^{1/n} = \sqrt[n]{a}` | +-------------------------------------+ >>> a,n = 2,3 >>> print(a**(1/n), np.cbrt(a)) 1.2599210498948732 1.25992104989 +-------------------------------------+ | :math:`a^{m/n} = \sqrt[n]{a^{m}}` | +-------------------------------------+ >>> a,m,n = 2,4,3 >>> print(a**(m/n), np.cbrt(a**m)) 2.5198420997897464 2.51984209979 +-------------------------------------+ | :math:`a^{mn} = (a^{m})^{n}` | +-------------------------------------+ >>> a,m,n = 2,4,3 >>> print(a**(m*n), (a**m)**n) 4096 4096 +-------------------------------------+ | :math:`\log(x^{y}) = y \log(x)` | +-------------------------------------+ >>> x,y = 4,2 >>> print(np.log(x**y),y * np.log(x)) 2.77258872224 2.77258872224 +-------------------------------------+ | :math:`\log_{a} a^{n} = n` | +-------------------------------------+ >>> x >>> x >>> x +--------------------------------------+ | :math:`\log(bc) = \log(b) + \log(c)` | +--------------------------------------+ >>> x >>> x >>> x +--------------------------------------+ | :math:`\log(\frac{1}{b}) = -log(b)` | +--------------------------------------+ >>> x >>> x >>> x Also recall that :math:`n^{0} = 1, \ 1! = 1, \ 0! = 1`