We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
+1
181
1
avatar+2448 

Need help, ty!

 Apr 23, 2018
 #1
avatar+101088 
+2

y  = x^2 - 8x + 13

 

Let's put this in vertex form....complete the square on x

 

y  = x^2 - 8x + 16 + 13   - 16       factor the first three terms....simplify the rest

 

y  = (x -4)^2   - 3 

 

The vertex of this parabola  is    (4, -3)  .....it opens upward

 

Notice that the line that would be tangent to this parabola at the vertex would be the line  y  = -3 ⇒  "B"

 

So....this is the line that intersects the parabola in only one place

 

To  get a feel for this look at the following graph :  https://www.desmos.com/calculator/8gai6us8zr

 

Note that the other lines either intersect the graph twice....or not at all

 

 

cool cool cool

 Apr 23, 2018

15 Online Users