Integrating sin(e^(-2x)) with Step-by-Step Solution

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Homework Statement



\int(sin (e^(-2x))) / e^(2x)


The Attempt at a Solution



so i set
u=e^2x
du=(e^2x)(2) dx

im kinda stuck on how to get rid of the e^-2x
 
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Set u=e^-2x instead.
Therefore, du/dx=-2u, that is dx=-du/2u

Use this to simplify your integrand!
 
k using u=e^-2x
du=-2 (e^-2x) dx

so...

-1/2 \int sin u du

-1/2 (-cos u) + c is that right?
 
Sure. But there is a simpler way to write (-1/2)*(-cos(u)).
 
so final answer is cos u /2
 
cos(u)/2+C. Use more parentheses. cos u /2 can also be read cos(u/2).
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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