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
112
1
avatar+1229 

The line \(x = k\) intersects the graph of the parabola \(x = -2y^2 - 3y + 5\) at exactly one point. What is k?

 Jul 16, 2019
 #1
avatar+103999 
+2

The line will be  x  =  the x coordinate of the vertex    =   k

 

The y coordinate of the vertex  =   - (-3) / 2(-2)  =  3 / -4  =  -3/4

 

The x coordinate of the vertex  =   -2(-3/4)^2 - 3(-3/4) + 5  =  -2(9/16) + 9/4 + 5  = 

 

(-9/8) + 18/8 + 40/8    =  49/8 

 

So....the line is

 

x  = 49/8  = k

 

Here's a graph :  https://www.desmos.com/calculator/yiurzdo46y

 

 

cool cool cool

 Jul 16, 2019

24 Online Users

avatar
avatar