Integrate by parts ? 15x sinx dx

1 Answer
Apr 10, 2018

#-15xcos(x)+15sin(x)+c#

Explanation:

#int(15xsin(x))dx#

Since #sin(x)# is a periodic function, it is going to be #u'#

#u'=sin(x)" "u=-cos(x)#
#v=15x" "v'=15#

#int(v*u')=v*u-int(v'*u)#

#int(15xsin(x))dx=-15xcos(x)-int(-15cos(x))dx#
#-15xcos(x)+int(15cos(x))dx=-15xcos(x)+15sin(x)+c#