Homework 15 problem 3 part 1
You’ll notice that the answer box looks like
Your answer is the supposed to be the [???], which (in our notation) is the anxn. Furthermore, they’ve already specified that they want a sum starting at n=0. So you you’ve got to specify your anxn so that the first term corresponds to n=0, which you haven’t quite done.
I think it should go like so:
Applying these same steps to the geometric series we get
This is almost what you’ve got, but I think you’ve got an error in your power of −1. Note, though, that I changed the starting index from n=0 to n=1 in the final step; we can do this since the zeroth term is zero (since we’re multiplying by n). When they say “shift the terms” they mean to add one to the n so that starting at zero in the new series is the same as starting at one in the old. Taking that into account, we get
And that (without the summation symbol) should the answer.
This does not seem to work for the answer either.
Did you type in my answer verbatim? Or did you include the parentheses that are obviously missing??
I did include the parentheses.