+0  
 
0
290
2
avatar+1442 

If we express $3x^2 + x - 4$ in the form $a(x - h)^2 + k$, then what is $k$?

AnonymousConfusedGuy  Oct 20, 2017
 #1
avatar+87655 
+2

3x^2 + x - 4      factor out the 3

 

3 [x^2 +  (1/3)x - (4/3) ]

 

Take (1/2) of (1/3)  = 1/6.......square this = 1/36......add it and subtract it

 

3 [ x^2 + (1/3)x  + 1/36 - (4/3) - 1/36 ]   factor the first 3 terms

 

3 [ ( x + 1/6)^2 - 1/36 - 48/36 ]

 

3 [ (x + 1/6)^2 - 49/36 ]

 

3(x + 1/6)^2 - 49/12

 

So k =  -49/12

 

 

cool cool cool

CPhill  Oct 20, 2017
 #2
avatar+1442 
+1

Thank you so much I was struggling with completing the square now I get it

AnonymousConfusedGuy  Oct 20, 2017

20 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.