∫[1→4] e^(√x) dx
令√x=u,则x=u²,dx=2udu,u:1→2
=∫[1→2] 2ue^u du
=2∫[1→2] u de^u
=2ue^u-2∫[1→2] e^u du
=2ue^u-2e^u |[1→2]
=4e²-2e²-2e+2e
=2e²
∫[1→4] e^(√x) dx
令√x=u,则x=u²,dx=2udu,u:1→2
=∫[1→2] 2ue^u du
=2∫[1→2] u de^u
=2ue^u-2∫[1→2] e^u du
=2ue^u-2e^u |[1→2]
=4e²-2e²-2e+2e
=2e²