+0  
 
0
273
1
avatar

The graph of the equation y=ax^2+bx-6 is completely below the x axis. If , a^2=49 what is the largest possible integral value of b?

 Jun 19, 2018
 #1
avatar+17331 
+1

This describes an upside down parabola (opens downward...looks like a dome)

so    a^2 = 49   means  a = -7

 

so you have   -7x^2+bx-6 =0        Using quadratic formula

 

\(0> {-b \pm \sqrt{b^2-4(7)(-6)} \over -14}\)   yields   b <12.96   and b  > -12.96  

                                                        so b<12.96 is the greatest value

 Jun 20, 2018

11 Online Users

avatar
avatar
avatar
avatar