Question #0be35

1 Answer
May 4, 2017

Answer:

#y=-x^2+10x-23#

Your answer is correct, I'm not sure why that website says the answer is wrong...

Explanation:

We have the vertex #(5,2)#, and the parabola has a negative #a# value because the graph is convex.

Looking at the other point (4,1), we can tell that the #a# value is equal to #-1# because of the slope, but just to confirm:

Vertex form: #color(blue)(y=a(x-h)+k)#
#y=a(x-5)^2+2#

Expand:
#y=a(x^2-10x+25)+2#

Try the point #(4,1)# to determine the value of #a#
#1=a(16-40+25)+2#
#1=a+2#
#a=-1#

#y=-(x^2-10x+25)+2#

#y=-x^2+10x-25+2#

#y=-x^2+10x-23#