Can someone tell me how to get the integral of x cos(x)?

Answer 1

hi
u can use integration by parts
answer is

x sin(x) + cos(x)

Answer 2

I'm not sure that this would be easy to type up. I can vaguely tell you that you will be doing integration by parts. u=x, dv=cos(x)dx, v=sin(x), and du=dx. The forumula is uv-the integral of vdu. Therefore the answer should be xsin(x)-the integral of sin(x)dx. This simplifies to xsin(x)+cos(x)+C.

It appears that the people who posted above me forgot the integration constant, C.

Answer 3

integration by parts
let u = x . . . . . . du = dx
. . .dv = cos x . . . v = sin x

integral of x cos x = x sin x - integral of sinx dx
. . . . . = x sin x + cos x

Answer 4

I = ∫ x.cosx dx = uv - ∫ v.(du/dx).dx
where u = x and dv/dx = cos x
du/dx = 1 and v = sin x
I = x.sin x - ∫ sin x .dx
I = x sin x + cos x + C