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Apr
17
answered Least Squares Approximation for odd functions question
Apr
17
comment Solve an Angle-Side-Angle special case triangle if it has an obtuse angle?
Why dont you try the law of sines? It works.
Apr
17
revised Compact sets of real number
added 9 characters in body
Apr
17
comment Compact sets of real number
Can you use that a continuous function on a compact set attains its minimum? Or that the product of compact spaces is compact?
Apr
17
answered Why does the result follow?
Apr
17
comment Insights in solving systems of eqn?
The for the moment forget about $I_3AI_4$, whatever that is. Try to obtain new - simpler - equations by adding / subtracting known equations. For example, add the first and third to immediately see what $x_3$ must be ...
Apr
17
answered If $xy=x^{-1}y^{-1}$, does this imply $x=x^{-1}$
Apr
17
comment Dual Vector Space embedding
In the first line you ask for an embedding, in the last line for a natural embedding. These are different questions (and have different answers).
Apr
17
comment Logarithm of a negative number
Nothing. You dropped the condition "whenever $a,b>0$" from the full steatement of the identity.
Apr
17
answered Continuity of 1/x
Apr
17
comment When do eigenvectors converge?
If $\{v_n\}_{n\in\mathbb N}$ is a sequence such that $A_nv_n=\lambda v_n$, it is not necessarily the case that $v_n$ converges in the first place. Think of $A=A_n=I$, $\lambda=\lambda_n=1$ for all $n$ and $v_n$ some "random" sequence.
Apr
17
comment Every integer greater than 1 is divisible by at least one prime. Can anyone please express this in logical notation
Do you have predicates for "is integer", "is greater than", "divides", "is prime" and a constant symbol for "1" available?
Apr
17
answered Exercises in combinatorics
Apr
17
comment Exercises in combinatorics
Where do cycles come from in 3)?
Apr
17
comment Irrationality of $\pi$ and circumference to diameter ratio.
Note that $\frac13$ also has "never ending numbers after decimal". This doesn't contradict the fact that $\frac13$ is finite.
Apr
17
answered Explain “There is a unique function from $\emptyset$ to any set $A$”.
Apr
17
answered How would Intermediate Value Theorem be used in this question?
Apr
17
revised How would Intermediate Value Theorem be used in this question?
added 8 characters in body
Apr
16
comment exercise involving exactness
I assume here monomorphism only means left-cancelable?
Apr
16
answered Regular Expressions Help