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location India
age 31
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seen 6 hours ago

A simple student.


1d
comment What is the motivation for quaternions?
@metacompactness: Suppose each number was expressed as $a_0+a_1i+a_2j$. Then letting $ij=a_0+a_1i+a_2j$ and multiplying on both sides by $i$ using field axioms shows that $j$ is a complex number. So unless we drop some of the field axioms we cannot get anything beyond complex numbers.
Aug
12
accepted Comparing a vector with a directed line segment
Aug
10
comment Comparing a vector with a directed line segment
Thanks for answering, but my question is still left unanswered. I perfectly understand that $x-y$ and $y-x$ are not the same since they have opposite directions. Please read the last two sentences again.
Aug
10
asked Comparing a vector with a directed line segment
Aug
6
reviewed Approve suggested edit on Proof of sequential limit theorem
Jul
31
comment Intuitive explanation of even/odd permutation
Thanks for the recommendation.
Jul
31
revised Intuitive explanation of even/odd permutation
added 159 characters in body
Jul
31
comment Intuitive explanation of even/odd permutation
(contd) My question is however is asking for a more general motivation of even/odd permutation for a fresh student. For example I used rotations in $D_n$ to motivate $\mathbb{Z}_n$. Likewise I was looking for a general motivation for even/odd permutations.
Jul
31
comment Intuitive explanation of even/odd permutation
Another way to look at it is to consider $S_n$ as the collection of matrices with rows of the identity matrix permuted. Your map above simply then becomes the determinant map. The even permutations go to $1$ and the odd permutations go to $-1$.
Jul
31
comment Intuitive explanation of even/odd permutation
Thanks. Another reason for calling them odd/even permutation is the parity of the number of inversions.
Jul
31
revised Intuitive explanation of even/odd permutation
added 238 characters in body
Jul
31
asked Intuitive explanation of even/odd permutation
Jul
29
comment Derivation of formula for finding median for grouped data
@Rahul: $L_m$ is the lower limit of the median class, $n$ is the total number of observations, $F_{m-1}$ is the cumulative frequency of the class preceding the median class, $f_m$ is the frequency of the median class, $c$ is the class width.
Jul
22
comment How can I find the median of this frequency distribution
I have also seen that the formula for median is sometimes given by letting $x=n/2$ in the above equation instead of $x=(n+1)/2$. Can you explain that?
Jul
2
awarded  Curious
Jul
2
awarded  Inquisitive
May
27
awarded  Popular Question
May
20
asked Newton's differential equation
May
17
comment $\lim_{x\to 2} \, \sqrt{x-2}$
In the real case note that the definition of limit of a function at a given point $x_0$ requires that there is an open interval containing $x_0$ such that the function is defined everywhere in $(a,b)$ except possibly at $x_0$. In your case there is no open interval containing $2$ where the function is defined. So the concept of limit existing is itself moot.
May
17
reviewed Approve suggested edit on Inequality of differential equation implies inequality of functions.