SOLUTION: Express f(x) = (5-x)(x+1) in standard form. f(x) = Find the vertex and axis of symmetry. vertex (x, y) = axis of symmetry =

Click here to see ALL problems on Trigonometry-basics

Question 1031177: Express f(x) = (5-x)(x+1) in standard form.
f(x) =

Find the vertex and axis of symmetry.
vertex (x, y) =

axis of symmetry =

Found 2 solutions by stanbon, Boreal:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
Express f(x) = (5-x)(x+1) in standard form.
f(x) = -x^2 -x+5x + 5 = -x^2 + 4x + 5
------------------------------------------
Find the vertex and axis of symmetry.
Vertex occurs when x = -b/(2a) = -4/(-2) = 2
f(2) = (5-2)(2+1) = 3*3 = 9
----
vertex (x, y) = (2,9)
axis of symmetry = x = 2
-----------------
Cheers,
Stan H.
-------------

Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website!
f(x)=(5-x)(x+1)=5x+5-x^2-x
=-x^2+4x+5. That is standard form. The roots will be (-1,5) to check.
The vertex is at -b/2a=-4/-2=2 for x.
f(2)=-4+8+5=9
(2,9) is the vertex.
axis of symmetry is x=2.