
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
May 13th, 2015, 07:46 AM  #1 
Newbie Joined: Oct 2014 From: England Posts: 12 Thanks: 0  my exam question
I had an exam today morning and I didn't answer this question because I can't even tell if it is inequalities or coordinate geometry 2x^2x 3=k has no real roots. Find the set of possible values of k. 
May 13th, 2015, 10:42 AM  #2 
Senior Member Joined: Mar 2011 From: Chicago, IL Posts: 214 Thanks: 77 
Let's write this quadratic equation in standard form: $\displaystyle 2x^2x(k+3)=0$ The discriminant of it is: $\displaystyle 1+4(2)(k+3)=8k+25$ Quadratic equation has no real roots if the discriminant is lesser than 0: $\displaystyle 8k+25<0$ $\displaystyle k<\frac{25}{8}$ 
May 15th, 2015, 11:58 AM  #3  
Newbie Joined: Oct 2014 From: England Posts: 12 Thanks: 0  Quote:
 

Tags 
exam, question 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Exam Question  BonaviaFx  Physics  1  April 7th, 2015 12:47 AM 
Question from exam about derivatives  OriaG  Calculus  1  February 10th, 2013 09:55 AM 
One more question and I am ready for exam  csoles  Elementary Math  2  March 21st, 2012 09:22 PM 
Hard exam Question  samuraibob  Linear Algebra  2  October 28th, 2010 08:06 AM 
Help on an exam question.  Stilianos  Calculus  2  November 5th, 2009 03:11 PM 