+0  
 
0
34
2
avatar+163 

What is the sum of all numbers a for which the graph of y=x^2+a and the graph of y=ax intersect one time?

 Dec 31, 2019
 #1
avatar+106519 
+2

y = x^2 + a

 

y  = ax

 

Set the y's equal

 

x^2  +  a  =  ax

 

x^2  - ax  + a    =  0

 

If we only have one solution, the discrminant  must  =  0

 

So

 

a^2  -  4a  =   0      factor

 

a ( a - 4)  =   0

 

The solutions are    a  =  0    or a  =   4

 

So....the sum of all possible  a's    =   4

 

 

cool cool cool

 Dec 31, 2019
 #2
avatar+163 
+1

I actually was working on this problem while you were, I also figured it out!!!

 Dec 31, 2019

16 Online Users

avatar