Hey, i have a question that asks
Show that the following function has exactly one zero in the given interval
f(x) = -(1/5)x^3 - (7/x^2) + (20/x), given interval (1, infinity)
i got f ' (x) already which is
(-3x^5-100x+70)/5x^3
and i know that it will cross 0 at 3 (by plugging f ' (x) into graph).. but how do i show that mathematically?
thanks!
Show that the following function has exactly one zero in the given interval
f(x) = -(1/5)x^3 - (7/x^2) + (20/x), given interval (1, infinity)
i got f ' (x) already which is
(-3x^5-100x+70)/5x^3
and i know that it will cross 0 at 3 (by plugging f ' (x) into graph).. but how do i show that mathematically?
thanks!