+0  
 
0
198
1
avatar

The grid lines in the graph below are one unit apart. The red parabola shown is the graph of the equation $y = ax^2 + bx + c.$ Find $a+b+c$. 

https://latex.artofproblemsolving.com/c/e/2/ce264d13e5e7038f82ba3bae952d91fdf182b0ff.png

 Feb 16, 2018
 #1
avatar+94526 
+1

The y intercept is (0, 5)....so  "c"  = 5

 

The vertex  is  (2,1)

 

The coordinate of the vertex  is

 

-b/[ 2a ]  =  2

-b = 4a

b = - 4a

 

And (1,2)  is on the graph....so we have that

 

2  =  a(1)^2  - 4a(1)  + 5

2  = a  - 4a  + 5

-3  = -3a

1  =  a

 

So   b = -4(1)  =  -4

 

a + b + c   =   1 - 4  + 5    =  2

 

 

cool cool cool

 Feb 16, 2018

12 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.