What is the equation of a parabola that has a vertex at ( 0,4 ) and passes through points ( 2,0 )?
1 answer:
Answer:
<u>y = -x² + 4</u>
Step-by-step explanation:
The equation of the parabola in the vertex form is:
y = a (x-h)² + k
Where: (h,k) the coordinates of the vertex & a is a multiplier
The parabola has a vertex at ( 0,4 )
So, h = 0 , k = 4
∴ y = a (x-0)² + 4
∴ y = a x² + 4
The parabola passes through points ( 2,0 )
∴ 0 = a 2² + 4
∴ 4 a = -4 ⇒ a = -4/4 = -1
∴ y = -x² + 4
So, the equation of a parabola that has a vertex at ( 0,4 ) and passes through points ( 2,0 ) is <u>y = -x² + 4</u>
See the attached figure.
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Answer:
<em>The coordinates of the vertex are (-1,-4).</em>
Step-by-step explanation:
<u>Equation of the Quadratic Function </u>
The vertex form of the quadratic function has the following equation:
Where (h, k) is the vertex of the parabola that results when plotting the function, and a is a coefficient different from zero.
We are given the function:
We must transform the equation above by completing squares:
The first two terms can be completed to be the square of a binomial. Recall the identity:
Thus if we add and subtract 1:
Operating:
The trinomial in parentheses is a perfect square:
Adding 4:
Comparing with the vertex form of the quadratic function, we have the vertex (-1,-4).
The coordinates of the vertex are (-1,-4).