SOLUTION: Find the vertex of the parabola. f(x)=-3x^2+16.2x-20.8

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Find the vertex of the parabola. f(x)=-3x^2+16.2x-20.8      Log On


   

Question 386167: Find the vertex of the parabola.
f(x)=-3x^2+16.2x-20.8
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
f(x) =3x^2+16.2x-20.8
to find the x coordinate of the vertex, use the formula, x=-b/2a
a=3, b=16.2
x=-16.2/2*3 =16.2/6=-2.7
to find the y-coordinate, substitute -2.7 for x in the given equation
y=3*(-2.7)^2+16.2*-2.7-20.8 =-42.67
ans: coordinates of the vertex are (-2.7,-42.67)
see the following graph
+graph%28+300%2C+200%2C+-6%2C+5%2C+-50%2C+10%2C+3x%5E2%2B16.2x-20.8%29+
note: you can also find the coordinates of the vertex by completing the square to come up with the form, y=(x-h)^2+k, with (h,k) being the (x,y) coordinates of the vertex.