t
-------------------
________________
/ 2
\/ 1 - (w*t + f)
$$\frac{t}{\sqrt{1 - \left(f + t w\right)^{2}}}$$
2
t *(f + t*w)
-------------------
3/2
/ 2\
\1 - (f + t*w) / $$\frac{t^{2} \left(f + t w\right)}{\left(1 - \left(f + t w\right)^{2}\right)^{\frac{3}{2}}}$$
/ 2 \
3 | 3*(f + t*w) |
t *|1 + --------------|
| 2|
\ 1 - (f + t*w) /
-----------------------
3/2
/ 2\
\1 - (f + t*w) / $$\frac{t^{3} \cdot \left(1 + \frac{3 \left(f + t w\right)^{2}}{1 - \left(f + t w\right)^{2}}\right)}{\left(1 - \left(f + t w\right)^{2}\right)^{\frac{3}{2}}}$$