1995 BC5 Question

Test Preparation
1

<p>The part c of this question is confusing me...I have NO idea how to do it. </p>

<p>c) Prove that the graph of y = x^2 + cos (kx) has either no points of inflection or infinitely many points of inflection, depending on the value of the constant K.</p>

<p>Anyone have any ideas?
Thanks a bunch.</p>

2

<p>if k is zero, the second derivative is a constant, thus no inflection point. When k is anything else, the second derivation is a somewhat cosinial function, making an infite amount of inflects.</p>

3

<p>That is correct.</p>