Given,
I=∫(x5+x3+1)32x12+5x9dx=∫x15(1+x21+x51)3(2x12+5x9)dx=∫(1+x21+x51)3(x32+x65)dxLet,
1+x21+x51=t ⇒(−x32−x65)dx=dt⇒(x32+x65)dx=−dtI=−∫t3dt=2.t21I=21(1+x21+x51)21+c=21(x5+x3+1)2x10+cWhere
c is the constant of integration.
=2(x5+x3+1)2x10+c