Write f(x) = x2 - 3x + 2 into vertex form?
Solution:
The vertex form of a quadratic function is f(x) = a(x - h)2 + k where a, h, and k are constants. The vertex of the parabola is at (h, k).
When the quadratic parent function f(x) = x2 is written in the vertex form , y = a(x - h)2 + k, a = 1, h = 0 and k = 0.
For the given quadratic equation f(x) = x2 - 3x + 2 the x coordinate of the vertex is given by the expression:
x = -b/2a
Where b = -3 and a = 1
x = h = -(-3)/2(1) = 3/2
Substituting the value of x in the given quadratic equation we get the value of the y coordinate which is
k = y = f(x) = (3/2)2 - 3(3/2) + 2 = 9/4 - 9/2 + 2
k = -9/4 + 2 = -1/4
The vertex is therefore (3/2, -1/4)
Now we have all the constants required to write the vertex form of the equation:
a = 1, h = 3/2 and k = -¼
The vertex form of the quadratic equation is:
(1)(x - 3/2)2 - 1/4
= (x - 3/2)2 - 1/4
Write f(x) = x2 - 3x + 2 into vertex form?
Summary:
The vertex form of the quadratic equation is (x - 3/2)2 - 1/4
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