Given ∫01xnexdx=In\int_{0}^{1} x^n e^x dx = I_n∫01xnexdx=In, which of the following reduction formulas is correct for InI_nIn?
In=e+nIn−1I_n = e + n I_{n-1}In=e+nIn−1
In=e−1nIn−1I_n = e - \frac{1}{n} I_{n-1}In=e−n1In−1
In=nIn−1−eI_n = n I_{n-1} - eIn=nIn−1−e
In=e−nIn−1I_n = e - n I_{n-1}In=e−nIn−1