Linked Questions

7 votes
1 answer
280 views

I'm looking for a closed-form of the following integral problem. $$I = \int_0^{\pi/2} \arctan(x)\cot(x)\,dx.$$ The numerical approximation of $I$ is $$I \approx 0....
user153012's user avatar
2 votes
1 answer
267 views

I keep trying to solve this but I end up needing to do integration by parts like 3 or 4 times. My only question is, is that going to be the only way to do this? If so it will literally take me hours. ...
user avatar
0 votes
2 answers
96 views

This is from an integral problems book, it is a part of the solution of a larger problem. $$\int_0^1\frac1{(x^2+4)^2}~dx=\frac18\Biggl( \Bigl(\frac x{x^2+4} \Bigr) \bigg\vert _0^1~+~\int_0^1\frac{dx}{...
Milan's user avatar
  • 1,711
1 vote
1 answer
240 views

I know how to integrate, for example $x^2\sin x$ via integration by parts. But how would one approach $x^n\sin x$, where $n$ is an arbitrary natural number? Do I have have to use integration by parts $...
Adam's user avatar
  • 3,680
4 votes
2 answers
177 views

The integral $$\int\frac{1}{(x^2+a^2)^m}dx$$ can be expressed by a recursive formula of $$\frac{1}{2a^2(m-1)}\frac{x}{(x^2+a^2)^{m-1}} + \frac{2m-3}{2a^2(m-1)}\int\frac{dx}{(x^2+a^2)^{m-1}}$$ I do not ...
Champayond's user avatar
0 votes
3 answers
214 views

I need to evaluate $$ \int_0^1 \dfrac 1{(x^2+1)^2}. $$ I was absent for this lecture and I'm sort of lost on where to go. I set $x = \tan (\theta)$ and $dx = \sec^2(\theta)\, d\theta$. And this ...
Sartree's user avatar
  • 35
0 votes
4 answers
120 views

I am integrating $$\pi\int\left(\cfrac{1}{x^2+4}\right)^2dx$$ I understand I need to integrate by parts. But why is it that $$u=\cfrac{1}{x^2+4}$$ and not $$u=\left(\cfrac{1}{x^2+4}\right)^2$$ How ...
Jinzu's user avatar
  • 869
1 vote
1 answer
85 views

How can I integrate: $$\int \frac{1}{(t^2+k^2)^m}\, dt$$ without trygonometric substituition? where $t= (x+(p/2))$ and $k= (1-(p^2/4))$ coming from an equation with complex roots: $x^2 + px + q.$ ...
Yassin Rany's user avatar
0 votes
1 answer
95 views

Compute $$\int_{-\pi/2}^{\pi/2} \frac{x^2\cos(x)}{1+e^x}$$ The first step itself given in the solution is changing $e^x$ to $1/e^x$ . Now as first step is making no sense to me so I didn't post the ...
Archis Welankar's user avatar
1 vote
3 answers
118 views

How to calculate the following integral if $\varepsilon \in (0,1)$: $$\int \limits_{0}^{\pi}\frac{d\varphi}{(1+\varepsilon\cos \varphi)^2}$$
RFZ's user avatar
  • 17.8k
0 votes
4 answers
88 views

I would like to know if there is an algebraic way to evaluate $$\int \frac{\text{d}x}{x^2(x^2+1)^2}$$ Without using partial fraction decomposition and without substitution. My attempt is something ...
Bernkastel's user avatar
  • 2,162
1 vote
1 answer
160 views

I know that $\displaystyle\int \dfrac1{ax^2+bx+c}\,\mathrm dx$ is easily solvable using completing the square, but my question is how would would find $$\displaystyle\int\frac{1}{\left(ax^2+bx+c\...
P W's user avatar
  • 69
1 vote
2 answers
152 views

So I was trying to use partial fraction decomposition on this problem, and I realized that it didn't work, as it is already in partial fraction decomposition form. $$\int{\frac{3x+4}{(x^2+5)^2}dx}$$ ...
moonrune's user avatar
0 votes
2 answers
85 views

I need to calculate: $$\int x^2 \cdot \cos{x} \cdot dx $$ My step by step solution: Using the formula: $$\int udv=uv-\int vdu$$ $\color{gray}{\boxed{\color{black}{\int x^2 ⋅ \cos{x}⋅ dx=x^2 \sin{x}-...
Andrew's user avatar
  • 61
1 vote
1 answer
159 views

Recently I've been looking around for integral tricks here, here, and here (just to name a few). I came across the post on brilliant's website here (move the slider/ scroll down to the very bottom to ...
ben ton's user avatar
  • 33

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