
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
May 8th, 2017, 05:14 AM  #1 
Newbie Joined: May 2017 From: Australia Posts: 2 Thanks: 0  Convert vertex form to standard form
Hi, I have a parabola with the following vertex info, I am trying to convert this to standard form (ax2 + bx + c), however I cannot seem to get the conversion correct. I have plots for the parabola and have created a trend line with equation in excel so I can compare and be confident my conversion is correct: Please see below, I have followed the rules for conversion but something is incorrect, if anyone could help it would be greatly appreciated and show the working out. y = a (x  h)^2 + K K = 114, h = 0, x = 255, y = 0 from this info I have derived a = 0.00175 from my excel trendline the standard form should be approx = y = 0.0018x^2 + 0.0027x + 116.44 thanks 
May 8th, 2017, 06:01 AM  #2 
Math Team Joined: Jul 2011 From: Texas Posts: 2,623 Thanks: 1303 
vertex form, $y=a(xh)^2+k$, expanded to standard form, $y=ax^2+bx+c$ yields ... $y=ax^2 + (2ah)x + (ah^2+k)$ note $b=2ah$ ... if $h=0$, then there is no linear term. 
May 21st, 2017, 03:34 AM  #3 
Newbie Joined: May 2017 From: Australia Posts: 2 Thanks: 0 
thanks skeeter, thats what I wanted. How do I convert a quartic form to vertex, so y = a (xh)^4 + K how does this equate in a quartic form:y = ax4 + (????)x + (????)x ..... etc thanks 
May 21st, 2017, 04:03 AM  #4 
Math Team Joined: Jul 2011 From: Texas Posts: 2,623 Thanks: 1303 
Use the binomial theorem to expand $(xh)^4$ then distribute $a$ ...


Tags 
convert, form, standard, vertex 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Help converting standard form of quadratic function to vertex form  abc98  Algebra  10  September 20th, 2015 05:49 PM 
Standard form and identify the vertex of a graph  kayna84  PreCalculus  1  July 30th, 2015 11:44 AM 
Converting Quadratics from standard form to Vertex form  PerfectTangent  Algebra  2  February 25th, 2014 09:18 PM 
standard and vertex form  Kinroh  Algebra  6  June 10th, 2012 08:18 PM 
Standard from/ vertex form problem  Tetra  Algebra  7  October 8th, 2009 06:23 PM 