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App developer, Research Associate, and Lecturer of and dabbler in Mathematics.


Sep
16
reviewed Approve suggested edit on Comparing the size of square roots
Sep
15
answered How to simplify abs(x)/x
Sep
15
reviewed Approve suggested edit on Prove that $\max\{|x_i|: 1 \leq i \leq n\} \leq \|\vec{x}\| \leq \sum_{i=1}^{n} |x_i|$
Sep
15
comment Special values $\psi \left(\frac12\right)$ and $\psi \left(\frac13\right)$
You may find it useful to work with the log-gamma function $\log\Gamma(z)$ since its derivative is $\Gamma'(z)/\Gamma(z)$.
Sep
15
revised The supremum of rationals that are less than a given number is equal to that number
deleted 1 character in body
Sep
15
reviewed Approve suggested edit on Again with this question. How to learn mathematics
Sep
15
revised Summation of $\sum_{k=0}^{n-1} z^k = 0$
updated the math notation
Sep
15
accepted Inverse Laplace Transform of $(s+1)/z^s$
Sep
15
comment Finding the definite integral of a function that contains an absolute value
No, the modulus is not meaningless for indefinite integrals. When considering definite integrals as your question does we have bounds on the integral, which tells us the domain of the integrand to consider. Because we know the domain, we also know the sign (positive/negative) of a given $x$ value. Hence we can then split the integral into positive/negative parts to evaluate it. Notice also that an indefinite integral can be written as a definite integral since $$\int f(x)dx = \int_\lambda^x f(t)dt,$$ where the "lower bound" $\lambda$ gives a constant of integration.
Sep
15
revised Finding the definite integral of a function that contains an absolute value
added 13 characters in body
Sep
15
comment Finding the definite integral of a function that contains an absolute value
@ surelyyourjoking. Then $x$ would only ever be a positive value (or zero) and so the modulus can be replaced simply by $x$ alone since $∣x∣≥0$ for all $x$.
Sep
15
comment Finding the definite integral of a function that contains an absolute value
@ surelyyourjoking. Then $x$ would only ever be a positive value (or zero) and so the modulus can be replaced simply by $x$ alone since $\mid x\mid\geq 0$ for all $x$.
Sep
15
answered Finding the definite integral of a function that contains an absolute value
Sep
15
comment Range of $\log(16-4x^2-4y^2-z^2)$
Wolfram Alpha: wolframalpha.com/input/…
Sep
14
reviewed Approve suggested edit on Finding Convergeance sum for two power-series.
Sep
14
reviewed Approve suggested edit on Probability of a 75% freethrow shooter making at least 5 shots in a row out of 10.
Sep
14
reviewed Approve suggested edit on Taylor Polynomial Accuracy
Sep
12
revised Useful device in complex analysis (Perron's formula)
added 182 characters in body
Sep
12
comment Useful device in complex analysis (Perron's formula)
@ Felix Marin ah yes, I can see that quite clearly now you mention it!
Sep
11
comment Useful device in complex analysis (Perron's formula)
@ robjohn Cool - I did think it was something to do with convergence. Thanks.