Integral of 1/(4+x^2) dx
The solution
Detail solution
We have the integral:
/
|
| 1
| ------ dx
| 2
| 4 + x
|
/
Rewrite the integrand
1 1
------ = --------------
2 / 2 \
4 + x |/-x \ |
4*||---| + 1|
\\ 2 / /
or
/
|
| 1
| ------ dx
| 2 =
| 4 + x
|
/
/
|
| 1
| ---------- dx
| 2
| /-x \
| |---| + 1
| \ 2 /
|
/
----------------
4
In the integral
/
|
| 1
| ---------- dx
| 2
| /-x \
| |---| + 1
| \ 2 /
|
/
----------------
4
do replacement
then
the integral =
/
|
| 1
| ------ dv
| 2
| 1 + v
|
/ atan(v)
------------ = -------
4 4
do backward replacement
/
|
| 1
| ---------- dx
| 2
| /-x \
| |---| + 1
| \ 2 / /x\
| atan|-|
/ \2/
---------------- = -------
4 2
Solution is:
/x\
atan|-|
\2/
C + -------
2
The answer (Indefinite)
[src]
/ /x\
| atan|-|
| 1 \2/
| ------ dx = C + -------
| 2 2
| 4 + x
|
/
∫x2+41dx=C+2atan(2x)
The graph
2atan(21)
=
2atan(21)
Use the examples entering the upper and lower limits of integration.