2.718 281 828 459 045 235 360 287 471 352 662 497 757 247.....
This number is the base for natural logarithms usually shown by Ln or ex on calculators.
e = (1 + 1/n)n
when n is a very large number (as close to infinity as practicable)
e = 1 + 1/1! + 1/2! + 1/3! + 1/4! + 1/5! + ....
e = (1 + n)(-n)
when n is a very small number (as close to zero as practicable)
e = ∑((2n + 2)/(2n +1)! )
(Sum from n=0 to n=infinity)
Pi (π)
3.141 592 653 589 793 238 462 643 383 279 502 884 197 169 399...
This number is used extensively in maths, physics and circles.
π = 4/1 - 4/3 + 4/5 - 4/7 + 4/9 - 4/11 + 4/13 - 4/15 ....
π = 3 + 4/2x3x4 - 4/4x5x6 + 4/6x7x8 - 4/8x9x10 + 4/10x11x12 - 4/12x13x14 + 4/14x15x16 ....
π = ∑( 16(-n) (4/(8n+1) - 2/(8n+4) - 1/(8n+5) - 1/(8n+6) ) )
Golden Ratio Φ
1.618 033 988 749 894 848 204 58....
Φ = (1+√5)/2
Euler-Mascheroni Constant γ
0.577 215 664 901 532 860 606 512 090 082 402 431 042 159 335 9...
γ = ∑(1/n) - Ln(n)
(Sum n=0 to n=very_large_number)
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