Mister Exam

Lang:

Other calculators

How to use it?
Integral of d{x}:
Integral of (1+x)/x
Integral of e^3
Integral of 1/(1+4x^2)
Integral of (sec(x))^3
Derivative of:
e^(-x)*cos(x)
Graphing y =:
e^(-x)*cos(x)
Limit of the function:
e^(-x)*cos(x)
Identical expressions
e^(-x)*cos(x)
e to the power of ( minus x) multiply by co sinus of e of (x)
e(-x)*cos(x)
e-x*cosx
e^(-x)cos(x)
e(-x)cos(x)
e-xcosx
e^-xcosx
e^(-x)*cos(x)dx
Similar expressions
e^(-x)cosx
e^(x)*cos(x)
e^(-x)*cosx

Solving integrals/ e^(-x)*cos(x)

Integral of e^(-x)*cos(x) dx

The solution

You have entered [src]

  1              
  /              
 |               
 |   -x          
 |  e  *cos(x) dx
 |               
/                
0

$$\int\limits_{0}^{1} e^{- x} \cos{\left(x \right)}\, dx$$

Integral(cos(x)/E^x, (x, 0, 1))

Detail solution

Use integration by parts, noting that the integrand eventually repeats itself.
1. For the integrand $e^{- x} \cos{\left(x \right)}$ :
  
  Let $u{\left(x \right)} = \cos{\left(x \right)}$ and let $\operatorname{dv}{\left(x \right)} = e^{- x}$ .
  
  Then $\int e^{- x} \cos{\left(x \right)}\, dx = - \int e^{- x} \sin{\left(x \right)}\, dx - e^{- x} \cos{\left(x \right)}$ .
2. For the integrand $e^{- x} \sin{\left(x \right)}$ :
  
  Let $u{\left(x \right)} = \sin{\left(x \right)}$ and let $\operatorname{dv}{\left(x \right)} = e^{- x}$ .
  
  Then $\int e^{- x} \cos{\left(x \right)}\, dx = \int \left(- e^{- x} \cos{\left(x \right)}\right)\, dx + e^{- x} \sin{\left(x \right)} - e^{- x} \cos{\left(x \right)}$ .
3. Notice that the integrand has repeated itself, so move it to one side:
  
  $2 \int e^{- x} \cos{\left(x \right)}\, dx = e^{- x} \sin{\left(x \right)} - e^{- x} \cos{\left(x \right)}$
  
  Therefore,
  
  $\int e^{- x} \cos{\left(x \right)}\, dx = \frac{e^{- x} \sin{\left(x \right)}}{2} - \frac{e^{- x} \cos{\left(x \right)}}{2}$
Now simplify:

$- \frac{\sqrt{2} e^{- x} \cos{\left(x + \frac{\pi}{4} \right)}}{2}$
Add the constant of integration:

$- \frac{\sqrt{2} e^{- x} \cos{\left(x + \frac{\pi}{4} \right)}}{2}+ \mathrm{constant}$

The answer is:

$- \frac{\sqrt{2} e^{- x} \cos{\left(x + \frac{\pi}{4} \right)}}{2}+ \mathrm{constant}$

The answer (Indefinite) [src]

  /                                           
 |                      -x                  -x
 |  -x                 e  *sin(x)   cos(x)*e  
 | e  *cos(x) dx = C + ---------- - ----------
 |                         2            2     
/

$${{e^ {- x }\,\left(\sin x-\cos x\right)}\over{2}}$$

Simplify

The graph

Plot the graph f(x)

The answer [src]

     -1                  -1
1   e  *sin(1)   cos(1)*e  
- + ---------- - ----------
2       2            2

$${{e^ {- 1 }\,\left(\sin 1-\cos 1\right)}\over{2}}+{{1}\over{2}}$$

     -1                  -1
1   e  *sin(1)   cos(1)*e  
- + ---------- - ----------
2       2            2

$$- \frac{\cos{\left(1 \right)}}{2 e} + \frac{\sin{\left(1 \right)}}{2 e} + \frac{1}{2}$$

Simplify

Numerical answer [src]

0.55539688265335

0.55539688265335

The graph

Use the examples entering the upper and lower limits of integration.

Other calculators

How to use it?

Identical expressions

Similar expressions

Integral of e^(-x)*cos(x) dx

Limits of integration:

The graph:

Piecewise:

The solution