Question

lim as x -> infinity ((e^-7x) cos x)

Answer 1

0

Answer 2

how?

Answer 3

I can't give you any method rather than this logic.
No matter how the value of x is big cos(x) is between -1and 1.
Thus forget about cos(x) and find the limit for e^-7x.
What do you think?

Answer 4

That's what I was thinking more or less, though I had things a little backwards. Thank you!!