Question 1115246
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<pre>
  6
  &#8747; x(x² + 3)² dx  = 
  1

     6
= {{{1/2}}}.&#8747; (x² + 3)^2*(dx²)  = 
     1

     6
= {{{1/2}}}.&#8747; (x² + 3)²*d(x²+3)  =   // make substitution/replacement  x²+3 ---> t;  1 --->  1^2+3 = 4;  6 ---> 6^2+3 = 39.  You will get
     1

    39
= {{{1/2}}}.&#8747; t^²*dt =   // it is just an elementary integral from the tables
     4

        |39
= {{{1/6}}}.{{{t^3}}} | = {{{1/6}}}.{{{(39^3-4^3)}}} = 9875.833.
        |4

</pre>

Solved.