Find the coordinates of points where the graph of f(x) has horizontal tangents. As a check, graph f(x) and see whether the points you found look as though they have horizontal tangents.

Question

f(x) = −x3 + 6x2 − 9x + 13
(x, y) = ( ? ) (smaller x-value)
(x, y) = ( ? ) (larger x-value)

Answer 1

same issue