If , then
I am thinking this might be able to be represented in a series but the coefficients are making that an issue. Maybe there is another way to tackle this?
I put this in this form because it wasn't necessarily to calculus based but it isn't exactly pre-calculus.
I might as well say this.
Once I saw that this was an official GRE publication, I knew the given answer had to be correct.
Nevertheless, I consider this to be a very poor question.
For one the given answer not in expected form.
I first thought this it was the obvious distracter because it is not usual to the minus there.
Only 26% got the question correct.
I hope this helps.
I am not adamant at nothing: I just liked the trick Hallsofivy introduced in his response [taking into account that . Just as I didn't check thorughly my work I didn't check his either, and after Plato intervened I did check it. There was only one lacking in Halls' work , and the way they put the answers in the GRE was very tricky ( I would even call it dirty ), no wonder Halls got confused:
This is pretty easy, but when you have 170 minutes to solve 66 questions this can be way misleading...so misleading as to be considered unfair, perhaps.
I still have to be explained, and convinced, what good is to have this kind of exams with those times....what do they REALLY check and evaluate.