Show that the equation x^3-15x+c=0 has at most one root in the interval [-2,2].

Question

Perhaps Rolle's Theorem, Mean Value Theorem, or Intermediate Value Theorem hold clues? ...Other than simply using my TI-84, I have no idea how to accomplish this.

Answer 1

See response:
http://www.jiskha.com/display.cgi?id=1298948844