$f(x) = 1 + \frac {7}{x} - \frac {5}{x^2}$
(a) Find the vertical asymptotes.
I answered $1$ because if you plug in $0$ for $x$ you get $1$.
(b) Find the interval where the function is increasing.
I answered ($\frac {7}{10}, \infty$) because I got $f'(x) = \frac {1}{x}(\frac{-7}{x} + 10)$ and solved for x.
(c) Find the interval where the function is decreasing.
I answered ($-\infty, \frac {7}{10}$)
(d) Find the local minimum and maximum values.
I answered local maximum $=$ DNE and local minimum $\approx$ .7959.
(e) Find the interval where the function is concave up.
I answered ($-\infty, \frac{7}{5}$) because I found $f''(x) = \frac{1}{x^2}(\frac{14}{x} - 10)$. Then I solved for $x$.
(f) Find the interval where the function is concave down.
I answered ($\frac{7}{5}, \infty$)
(g) Find the inflection point.
I answered ($\frac{7}{5}, 3.45$)
According to WebAssign, I got all of these wrong. How come? Please help!