
How to find a general sum formula for the series: …
2014年11月17日 · $5+55+555+5555+55555+\cdots n$ terms, Sum of finite seqence of this pattern can be obtained by re-arranging this into geometric sequence. $5$ should be taken …
A "fast" way to find the sum of the sequence …
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Why do we generally round 5's up instead of down?
2013年3月5日 · WE do this because when you round, generally it is with decimals that are rational or long. When there is 5.000000000000000001, it is better to round up. So, lets say you have …
Given the numerical succession 5, 55, 555, 5555, 55555... Are there ...
2017年4月13日 · $\begingroup$ Using modular arithmetic, you can certainly end up with basically the so-called "divisibility criteria" by $9$, $11$ and $5$ (respectively: sum of the digits divisible …
arithmetic - What's wrong with this fake proof that $2+2=5 ...
2017年9月28日 · Case in point, $3^2=(-3)^2$ and, as isyoung points out, $0.5^2=(-0.5)^2$. So, this fake-proof is designed to have one side equal to $0.5^2$ but the other side equal to $( …
Upper and lower bounds - nearest 5 - Mathematics Stack Exchange
2017年10月27日 · By halving 5 (the number you are rounding to) = 2.5 Then to find the upper bound you add it to the number you are rounding so 135 + 2.5 = 137.5 ( this is a multiple of 5). …
Formula for the simple sequence 1, 2, 2, 3, 3, 4, 4, 5, 5 ...
The formula below uses the floor function. $\lfloor x\rfloor$ denotes the floor function of x. For example, $\lfloor2\rfloor=2$ while $\lfloor2.5\rfloor=2$. For more on the floor and ceiling …
How to solve exponential equations like $2^x+x=5$?
2019年5月21日 · Then, $2^{5-y}=y \implies y \cdot 2^y=32$ Taking the log of both sides yields $$\log_2 y + y = 5$$ And that's where I'm stuck. Skip to main content Stack Exchange Network
Formula for $1^2+2^2+3^2+...+n^2$ - Mathematics Stack …
Or one might repeatedly apply the difference operator. For example, the first few values are 0, 1, 5, 14, 30, 55... Then the first set of differences is 1, 4, 9, 16, 25... The second set of …
abstract algebra - Group presentation of $A_5$ with two …
2016年11月4日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for …