Calculate the define integral?

Question

1. 13e^-(cos(x)) sin(x) dx

** sin(x) is not part of the exponent
[ 0 , pi/2]

Answer 1

Int 13e^-(cos(x)) sin(x) dx

let u = -cos(x)
du = sin(x)dx

Int = Int 13 e^u du
= 13 e^u + C
= 13 e^-cos(x) + C

Answer 2

Well..... I see it as 13e^(-cos(x)) from 0 to π/2. Now it's just plug 'n chug.

Doug