Integral of 1/ch(x)^3 dx
The solution
The answer (Indefinite)
[src]
/ / /x\\ /x\ 3/x\ 4/x\ / /x\\ 2/x\ / /x\\
| atan|tanh|-|| tanh|-| tanh |-| tanh |-|*atan|tanh|-|| 2*tanh |-|*atan|tanh|-||
| 1 \ \2// \2/ \2/ \2/ \ \2// \2/ \ \2//
| -------- dx = C + ------------------------- + ------------------------- - ------------------------- + ------------------------- + -------------------------
| 3 4/x\ 2/x\ 4/x\ 2/x\ 4/x\ 2/x\ 4/x\ 2/x\ 4/x\ 2/x\
| cosh (x) 1 + tanh |-| + 2*tanh |-| 1 + tanh |-| + 2*tanh |-| 1 + tanh |-| + 2*tanh |-| 1 + tanh |-| + 2*tanh |-| 1 + tanh |-| + 2*tanh |-|
| \2/ \2/ \2/ \2/ \2/ \2/ \2/ \2/ \2/ \2/
/
$$\int \frac{1}{\cosh^{3}{\left(x \right)}}\, dx = C + \frac{\tanh^{4}{\left(\frac{x}{2} \right)} \operatorname{atan}{\left(\tanh{\left(\frac{x}{2} \right)} \right)}}{\tanh^{4}{\left(\frac{x}{2} \right)} + 2 \tanh^{2}{\left(\frac{x}{2} \right)} + 1} - \frac{\tanh^{3}{\left(\frac{x}{2} \right)}}{\tanh^{4}{\left(\frac{x}{2} \right)} + 2 \tanh^{2}{\left(\frac{x}{2} \right)} + 1} + \frac{2 \tanh^{2}{\left(\frac{x}{2} \right)} \operatorname{atan}{\left(\tanh{\left(\frac{x}{2} \right)} \right)}}{\tanh^{4}{\left(\frac{x}{2} \right)} + 2 \tanh^{2}{\left(\frac{x}{2} \right)} + 1} + \frac{\tanh{\left(\frac{x}{2} \right)}}{\tanh^{4}{\left(\frac{x}{2} \right)} + 2 \tanh^{2}{\left(\frac{x}{2} \right)} + 1} + \frac{\operatorname{atan}{\left(\tanh{\left(\frac{x}{2} \right)} \right)}}{\tanh^{4}{\left(\frac{x}{2} \right)} + 2 \tanh^{2}{\left(\frac{x}{2} \right)} + 1}$$
$$\frac{\pi}{4}$$
=
$$\frac{\pi}{4}$$
Use the examples entering the upper and lower limits of integration.