sábado, 18 de junho de 2011

Count On Me (Bruno Mars)


If you ever find yourself stuck in the middle of the sea,
I'll sail the world to find you
If you ever find yourself lost in the dark and you
can't see,
I'll be the light to guide you
Find out what we're made of
What we are called to help our friends in need
You can count on me like one, two, three
I'll be there
And I know when I need it I can count on you like
Four, three, two
And you'll be there
Cause that's what friends are supposed to do,
Oh yeah
Wooooh, wooooh
If you're tossing and you're turning
and you just can't fall asleep
I'll sing a song beside you
And if you ever forget how much you really mean to me
Everyday I will remind you
Oh
Find out what we're made of
When we are called to help our friends in
need.

domingo, 5 de junho de 2011

MatLab® para Engenharia (11)

Resolução de Integrais Indefinidas:

Continuamos a utilização do comando syms, pois ainda estamos utilizando variáveis e expressões simbólicas.

Os passos de resolução de integral é como os de derivada, só que invés de usarmos o comando diff (de derivada), utilizamos o comando int (de integral). Veja como é simples:

>> int(x^3-2*x^2+8)

ans =

(x*(3*x^3 - 8*x^2 + 96))/12


 

>> int(1/x)

ans =

log(x)


 

>> int((x^2)/((x^3-2)^(1/2)))

ans =

(2*(x^3 - 2)^(1/2))/3


 

>> int((exp(cos(x)))*sin(x))

ans =

-exp(cos(x))


 

>> int(coth(2*x))

ans =

log(sinh(2*x))/2


 

>> int(log(x^2))

ans =

x*(log(x^2) - 2)


 

>> int(cos(x)*exp(x))

ans =

(exp(x)*(cos(x) + sin(x)))/2


 

>> int((sinh(2*x))*(exp(x)))

ans =

1/(2*exp(x)) + exp(3*x)/6


 

Integração dupla: Faz-se como em resolução de derivadas de ordem superior:

>> int(int(x^2))

ans =

x^4/12


 

>> int(int(cos(2*x)))

ans =

sin(x)^2/2 - 1/4


 

>> int(int(log(x)))

ans =

(x^2*(2*log(x) - 3))/4