Question

integral of 1/( e^(t+y) ) dy...?

Answer 1

equal
integral of e^-(t+y) = e^(-t-y)

Answer 2

u=(-t-y)
du- -dy

Answer 3

=-1/(e^(t+y))

Answer 4

what would du be if u = -t-y..?

Answer 5

-1

Answer 6

is it 1-dy..?

Answer 7

-dy

Answer 8

t is constant so its derivative is 0

Answer 9

oo gosh ofcourse..thanks you!

Answer 10

e^(t+y) = e^t * e^y
hint

Answer 11

and because e^t is a constant you can take it out of the integral and work with e^y