Question

What can you say about the inflection points of a cubic curve y=ax^3+bx^2+cx+d where a does not equal 0? Give reasons for your answer.

Answer 1

How does an inflection point occur? Answer: where the second derivative of y = 0-->

y''= 6ax+2b = 0, so x=-b/(3a) (a cannot be 0 because you would be dividing by 0)

Answer 2

Note that second derivative = 0 is a necessary but not sufficient condition for a point of inflection.

http://en.wikipedia.org/wiki/Point_of_inflection

Answer 3

thanks

Answer 4

Thank you!