Processing math: 100%
 
+0  
 
0
965
2
avatar

which data set best describe by the function y=2x squared+5x

 Apr 22, 2014

Best Answer 

 #2
avatar+118703 
+5

y=2x2+5x It is a concave up parabola because the coeffeicient of x2 is positivey=x(2x+5)

When y=0 x=0 or x=-5/2 

So the roots are x=0 and x=-5/2

The axis of symmetry is the average of the 2 roots x=-5/4

When x=-5/4

y=2\times\frac{25}{16}+5\times\frac{-5}{4}\\\\ y=\frac{25}{8}+\frac{-25}{4}\\\\ y=\frac{25}{8}+\frac{-50}8}\\\\ y=\frac{-25}{8}\\\\ \mbox{ therefore}\\\\ \mbox{Vertex is }\left(-1\frac{1}{4},-3\frac{1}{8}\right)

Just as CPhill said.    

 Apr 23, 2014
 #1
avatar+130477 
+5

Re: which data set best describe by the function y=2x squared+5x

-----------------------------------------------------------------------------------------------------

It's a parabola opening "upward' with its vertex at (-1.25, -3,125) 

 Apr 22, 2014
 #2
avatar+118703 
+5
Best Answer

y=2x2+5x It is a concave up parabola because the coeffeicient of x2 is positivey=x(2x+5)

When y=0 x=0 or x=-5/2 

So the roots are x=0 and x=-5/2

The axis of symmetry is the average of the 2 roots x=-5/4

When x=-5/4

y=2\times\frac{25}{16}+5\times\frac{-5}{4}\\\\ y=\frac{25}{8}+\frac{-25}{4}\\\\ y=\frac{25}{8}+\frac{-50}8}\\\\ y=\frac{-25}{8}\\\\ \mbox{ therefore}\\\\ \mbox{Vertex is }\left(-1\frac{1}{4},-3\frac{1}{8}\right)

Just as CPhill said.    

Melody Apr 23, 2014

3 Online Users

avatar
avatar