+0  
 
0
166
1
avatar

 

 Mar 19, 2018
 #1
avatar+21299 
+1

Help needed with the coordinates of points of intersection!

a:

\(\begin{array}{|rcll|} \hline y &=& x^2-6x \\ y &=& -8 \\\\ x^2-6x &=& -8 \\ x^2-6x+8 &=& 0 \\ x &=& \dfrac{6\pm \sqrt{36-4\cdot 8}}{2} \\ x &=& \dfrac{6\pm \sqrt{4}}{2} \\ x &=& \dfrac{6\pm 2}{2} \\ x &=& 3\pm 1 \\ \\ x_1 &=& 4 \qquad y_1 = -8 \\ x_2 &=& 2 \qquad y_2 = -8 \\ \hline \end{array} \)

 

 

b:

\(\begin{array}{|rcll|} \hline y&=& x^2-24 \\ y &=& -2x \\\\ x^2-24 &=& -2x \\ x^2+2x-24 &=& 0 \\ x &=& \dfrac{-2\pm \sqrt{4-4\cdot (-24)}}{2} \\ x &=& \dfrac{-2\pm \sqrt{100}}{2} \\ x &=& \dfrac{-2\pm 10}{2} \\ x &=& -1\pm 5 \\\\ x_1 &=& 4 \qquad y_1 = -2\cdot 4 = -8 \\ x_2 &=& -6 \qquad y_2 = -2\cdot (-6) = 12 \\ \hline \end{array}\)

 

laugh

 Mar 19, 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.