Integral of [x+3/√9-x²] dx?

1 Answer
Apr 21, 2018

#=>I=sqrt(9-x^2)+3sin^-1(x/3)+C

Explanation:

Your Question:

#int[x+3/√9-x²] dx#
I have noted that you are trying to ask question several times.

After observing your questions ,I think that your question is:

#color(blue)(I=int(x+3)/sqrt(9-x^2)dx#

#=>I=intx/sqrt(9-x^2)dx+int3/sqrt(9-x^2)dx#

#=>I=I_1+3int1/sqrt(3^2-x^2)dx#

#=>I=I_1+3sin^-1(x/3)+c'...to(A)#

Where, #I_1=intx/sqrt (9-x^2)dx#

Take, #sqrt(9-x^2)=u=>9-x^2=u^2=>x^2=9-u^2#

#=>2xdx=2udu=>xdx=udu#

So,

#I_1=intu/udu=int1du=u+c=sqrt(9-x^2)+c#

Substituting #I_1# in #(A)#,we get

#:.I=sqrt(9-x^2)+c+3sin^-1(x/3)+c'#

#=>I=sqrt(9-x^2)+3sin^-1(x/3)+C,where, C=c+c'#