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seen Nov 18 at 14:38

Oct
17
reviewed Reviewed Determining sign of integral
Oct
17
suggested approved edit on Determining sign of integral
Oct
17
reviewed Reviewed Reflection principle
Oct
17
comment Reflection principle
What have you done so far?
Oct
17
revised Potence of Euler's Number
added two tags
Oct
17
suggested approved edit on Potence of Euler's Number
Oct
16
comment Prove that $w=\frac{\sqrt{z^2+z+1}}{z^2-3z+2}$ analytic on $|z|<1$
Why dont you write $z^2 - 3 z + 2 = (z - 1)(z -2)$ and $z^2 + z + 1 = \big(z + e^\frac{i \pi}{3}\big) \big(z + e^{-\frac{i \pi}{3}}\big)$ and see what happens with the poles and the branches of $$ f(z) = \frac{\sqrt{\big(z + e^\frac{i \pi}{3}\big)} \sqrt{\big(z + e^{-\frac{i \pi}{3}}\big)}}{(z - 1)(z -2)}$$ for $|z|<1$? See here for the branches.
Oct
16
answered Motivation For Biology Students
Oct
16
comment shock waves characteristics
Also, if I understand your work, the method you are using is for solving fully nonlinear first order PDE's, and you are using it wrong. Your problem is quasilinear, and there is no need to introduce $p$ and $q$. This are only introduced in the case the derivatives of $u$ are involved nonlinearly in the equation. I strongly suggest you to study the first chapter of John's Partial Differential Equations, as I believe you are very confused. Any doubts, we can try to help.
Oct
16
comment shock waves characteristics
As timur comments, the characteristic equations are wrong. They should be stated against a parameter, not the involved variables. You are mistaking $t$ with $y$. The construction of the characteristics is based on the supposition that if $x = x(\eta)$ and $t = t(\eta)$, then $$\frac{d}{d\eta}u\big(x(\eta),t(\eta)\big) = u_x x'(\eta) + u_t t'(\eta) = u^2 u_x + u_t = 0$$ and then one says $x'(\eta) = u^2$, $t'(\eta) = 1$, $u'(\eta) = 0$. See my answer for a full analysis.
Oct
16
answered shock waves characteristics
Oct
16
comment The derivative of $f(t, y(t))$ with respect to $t$?
@F'OlaYinka Really? Any multivariable calculus textbook will have the construction. A good introductory textbook is Marsden and Tromba's Vector Calculus.
Oct
16
revised The derivative of $f(t, y(t))$ with respect to $t$?
added tag multivariable-calculus
Oct
16
suggested approved edit on The derivative of $f(t, y(t))$ with respect to $t$?
Oct
16
answered The derivative of $f(t, y(t))$ with respect to $t$?
Oct
16
revised Showing a certain operator is trace class.
formatted link
Oct
16
comment Showing a certain operator is trace class.
You can make nice links by using the code [nice link description](http://nicelink.direction.here/nicelink)
Oct
16
suggested approved edit on Showing a certain operator is trace class.
Oct
16
comment Elementary Question about limits
But if you are really too lazy to do it, a quick example would be $\sin x \sim x$ for small $x$. What does that say of $\sin^3 x$? And so on.
Oct
16
revised Elementary Question about limits
corrected tex