C3 January 2013 integration question

On this question, shouldn't you do integration by parts? on the mark scheme it's as if they've completely forgot about how it's multiplied by x, am i missing something really simple here?

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Original post by lucyjane_x

On this question, shouldn't you do integration by parts? on the mark scheme it's as if they've completely forgot about how it's multiplied by x, am i missing something really simple here?

No, they've done it by recognition. Use the substitution u = x^2 + 3 if you can't spot it.

The integral is of the form derivative of function * (function)^(a number) so integration to function^(number +1) / (number + 1)

Reply 2

lucyjane_x

OP

8

Original post by Zacken

No, they've done it by recognition. Use the substitution u = x^2 + 3 if you can't spot it.

The integral is of the form derivative of function * (function)^(a number) so integration to function^(number +1) / (number + 1)