Asked by bern
how to find the integral of (3x+pi)cos3xdx from [pi over 6, pi over 3}
Answers
Answered by
Damon
integrate by parts
int u dv = u v - int v du
dv = cos 3 x dx
so
v = (1/3) sin 3x
u = 3 x + pi
du = 3 dx
so
u v - (3/3)integral of sin 3x dx
put in your limits
(3x+pi)(sin 3x)- int sin3x dx
at pi/3 minus at pi/6
int u dv = u v - int v du
dv = cos 3 x dx
so
v = (1/3) sin 3x
u = 3 x + pi
du = 3 dx
so
u v - (3/3)integral of sin 3x dx
put in your limits
(3x+pi)(sin 3x)- int sin3x dx
at pi/3 minus at pi/6
Answered by
bern
i really appreciate the work it helps me a lot thank you