91Ó°ÊÓ

Determine the value of the upper limit of integration \(b\) for which a substitution converts the integral on the left to the integral on the right. \(\int_{0}^{b}\left(4 x^{3}+2 x\right) \sin \left(x^{4}+x^{2}\right) d x=\int_{0}^{\pi} \sin (u) d u\)

Determine the value of the upper limit of integration \(b\) for which a substitution converts the integral on the left to the integral on the right. \(\int_{1}^{b}(x+1) \exp (1 / x-\ln (x)) / x^{2} d x=\int_{1 / 4}^{1} \exp (u) d u\)