<p>Remember this one? It wasn't towards the end but it gave me trouble. I put when x=k because (k-k)^2 would equal zero....</p>
<p>any thoughts?</p>
<p>Answer is "k" because it equals 0 and -k-k equals a negative squared which is a positive so the answer has to be "k."</p>
<p>Oh yeah, I put k. It seemed too simple, though.</p>
<p>Calculus for the win!</p>
<p>p(x)=a(x-k)^2</p>
<p>dy/dx = 2a(x-k)</p>
<p>setting the derivative equal to 0</p>
<p>0=x-k</p>
<p>x=k</p>
<p>Voila</p>
<p>Okay, I didn't understand at all, but my answer is correct. :)</p>
<p>yeah i havent taken calc yet, but i too got k. :)</p>
<p>calculator for the win. substitute numbers.</p>
<p>gg, I can't believe I forgot to use my calculator for that problem.</p>
<p>y=a(x-k)^2 is a parabola open up with a vertex in (k, 0).
y(min) = 0 for x=k.</p>
<p>plugging in numbers works (incase you dont get the calculus like me ahah :)</p>
<p>LOL! i used calculus too for that! hahahaha</p>
<p>wasn't this question from the experimental section?</p>
<p>@sunburn -> I suppose not, because so many people here have got it.</p>
<p>I got k too.</p>