+0  
 
+5
678
2
avatar

what is the vertex of this equation 3x^2-11x-4=y

 Mar 6, 2017

Best Answer 

 #1
avatar+128460 
+5

3x^2-11x-4=y

 

We have the form

 

Ax^2 + Bx + C   = y

 

The x coordinate of the vertex is given by :  -B/ (2A)  = - (-11) / (2*3)  = 11/6

 

To find the y coordinate.....put this x value back into the function....and we have

 

3(11/6)^2 - 11(11/6) - 4

 

3(121/36) - 121/6 - 4

 

121/12 - 121/6 - 4

 

121/12 - 242/12 - 48/12  =

 

-169/12

 

So....the vertex is ( 11/6, -169/12 )

 

 

cool cool cool

 Mar 6, 2017
 #1
avatar+128460 
+5
Best Answer

3x^2-11x-4=y

 

We have the form

 

Ax^2 + Bx + C   = y

 

The x coordinate of the vertex is given by :  -B/ (2A)  = - (-11) / (2*3)  = 11/6

 

To find the y coordinate.....put this x value back into the function....and we have

 

3(11/6)^2 - 11(11/6) - 4

 

3(121/36) - 121/6 - 4

 

121/12 - 121/6 - 4

 

121/12 - 242/12 - 48/12  =

 

-169/12

 

So....the vertex is ( 11/6, -169/12 )

 

 

cool cool cool

CPhill Mar 6, 2017
 #2
avatar+26367 
+5

what is the vertex of this equation 3x^2-11x-4=y

 

Formula:

\(\begin{array}{|rcll|} \hline ax^2+bx+c &=& 0 \\\\ x_v &=& -\frac{b}{2a} \\ y_v &=& c - \frac{b^2}{4a} \\ \hline \end{array}\)

 

Vertex:

\(\begin{array}{|rcll|} \hline y &=& 3x^2-11x-4 \quad & | \qquad a = 3 \qquad b=-11 \qquad c = -4 \\\\ x_v &=& -\frac{(-11)}{2\cdot 3} \\ &=& \frac{11}{6} \\ \mathbf{x_v} &\mathbf{=}& \mathbf{1.8\bar{3}} \\\\ y_v &=& -4 - \frac{(-11)^2}{4\cdot 3} \\ &=& -4 - \frac{121}{12} \\ &=& -\frac{169}{12} \\ \mathbf{y_v} &\mathbf{=}& \mathbf{-14.08\bar{3}} \\ \hline \end{array}\)

 

laugh

 Mar 6, 2017

3 Online Users

avatar
avatar