+0  
 
0
53
4
avatar+62 

If we express 3x^2-6x-2 in the form a(x-h)^2+k what is a+h+k

 

Thanks this one confused me

AnonymousConfusedGuy  Oct 22, 2017
Sort: 

4+0 Answers

 #1
avatar+26328 
+1

Same process as for https://web2.0calc.com/questions/the-quadratic-x-2-20x-36-can-be-written-in-the-form, except you now compare the coefficient of the x^2 term as well.

 

a(x - h)^2 + k → a(x^2 - 2hx + h^2) + k → ax^2 - 2ahx + ah^2 +k

 

coeff of x^2:   a = 3

 

coeff of x:      -2ah = -6

 

constant;      ah^2 + k = -2

 

I'll leave you to complete it!

Alan  Oct 22, 2017
edited by Alan  Oct 22, 2017
 #2
avatar+62 
+1

So the answer would be -7?

AnonymousConfusedGuy  Oct 22, 2017
 #3
avatar+62 
+1

no -7 didn't work can you tell me how to complete it please?

AnonymousConfusedGuy  Oct 22, 2017
 #4
avatar+26328 
+1

Well, we have:

 

coeff of x^2:   a = 3

 

coeff of x:      -2ah = -6  → -2*3*h = -6  → 6h = 6  →  h = 1

 

constant;      ah^2 + k = -2 →  3*(1^2) + k = -2  →  3 + k = -2  →  k = -5

 

 

Hence  a + h + k = 3 + 1 - 5  or  a + h + k = -1

Alan  Oct 22, 2017

23 Online Users

avatar
avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details