SOLUTION: Use the method of completing the square to find the standard form of the quadratic function. f(x) = x^2 − 10x + 4 y =___ State the vertex and axis of symmetry of the graph

Algebra ->  Inequalities -> SOLUTION: Use the method of completing the square to find the standard form of the quadratic function. f(x) = x^2 − 10x + 4 y =___ State the vertex and axis of symmetry of the graph      Log On


   



Question 1130868: Use the method of completing the square to find the standard form of the quadratic function.
f(x) = x^2 − 10x + 4
y =___
State the vertex and axis of symmetry of the graph of the function.
axis of symmetry x=____
vertex (x, y) =

Found 2 solutions by josgarithmetic, htmentor:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
-------------------------------
f(x) = x^2 − 10x + 4
-------------------------------

x%5E2-10x%2B5%5E2%2B4-5%5E2
%28x-5%29%5E2%2B4-25
highlight%28%28x-5%29%5E2-21%29


VERTEX, (5,-21)
SYMMETRY AXIS, x=5

Answer by htmentor(1343) About Me  (Show Source):
You can put this solution on YOUR website!
f(x) = x^2 − 10x + 4
To complete the square for x^2 - 10x, since the linear term is -10, the constant term must be half of this, or -5:
(x - 5)^2 = x^2 - 10x + 25
25 = 21 + 4, so we need to subtract 21 to retain the original equation:
f(x) = (x - 5)^2 - 21
The standard form for a quadratic is y = a(x - h)^2 + k, where (h,k) is the vertex
Thus the vertex is (5,-21), and the axis of symmetry is x = 5