1955 AHSME Problems/Problem 39

Revision as of 17:37, 12 February 2021 by Justinlee2017 (talk | contribs) (Solution)

Solution

The least possible value of $y$ is given at the $y$ coordinate of the vertex. The $x$- coordinate is given by \[\frac{-p}{(2)(1)} = \frac{-p}{2}\] Plugging this into the quadratic, we get \[y = \frac{p^2}{4} - \frac{p^2}{2} + q\] \[0 = \frac{p^2}{4} - \frac{2p^2}{4} + q\] \[0 = \frac{-p^2}{4} + q\] \[q = \frac{p^2}{4} = \boxed{B}\]

~JustinLee2017