Find the End Behavior -2r^5+4r^3+9r-7

$- 2 r^{5} + 4 r^{3} + 9 r - 7$

Write $- 2 r^{5} + 4 r^{3} + 9 r - 7$ as a function.

$f (r) = - 2 r^{5} + 4 r^{3} + 9 r - 7$