Difference between revisions of "1955 AHSME Problems/Problem 39"

(Wrote a Solution for this problem, since it didn't have one.)
 
(Solution)
Line 5: Line 5:
 
<cmath>y = \frac{p^2}{4} - \frac{p^2}{2} + q</cmath>
 
<cmath>y = \frac{p^2}{4} - \frac{p^2}{2} + q</cmath>
 
<cmath>0 = \frac{p^2}{4} - \frac{2p^2}{4} + q</cmath>
 
<cmath>0 = \frac{p^2}{4} - \frac{2p^2}{4} + q</cmath>
<math></math>0 = \frac{-p^2}{4} + q$
+
<cmath>0 = \frac{-p^2}{4} + q</cmath>
 
<cmath>q = \frac{p^2}{4} = \boxed{B}</cmath>
 
<cmath>q = \frac{p^2}{4} = \boxed{B}</cmath>
  
 
~JustinLee2017
 
~JustinLee2017

Revision as of 17:37, 12 February 2021

Solution

The least possible value of $y$ is given at the $y$ coordinate of the vertex. The $x$- coordinate is given by \[\frac{-p}{2}\]. 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