SOLUTION: Vertex (1,3); passing through (2,6)

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Question 1176694: Vertex (1,3); passing through (2,6)
Found 2 solutions by Solver92311, math_tutor2020:
Answer by Solver92311(821) About Me  (Show Source):
You can put this solution on YOUR website!

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My calculator said it, I believe it, that settles it

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Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

Recall that
y+=+a%28x-h%29%5E2+%2B+k
represents the generalized vertex form.
a = leading coefficient
h = x coordinate of vertex
k = y coordinate of vertex

Since the vertex given to us is (1,3), this means (h,k) = (1,3)
In other words,
h = 1
k = 3

We're also told the parabola passes through (x,y) = (2,6)
x = 2
y = 6


We have these four items of info
h = 1
k = 3
x = 2
y = 6

Plug those four items into the first equation mentioned and isolate 'a'.
y+=+a%28x-h%29%5E2+%2B+k

6+=+a%282-1%29%5E2+%2B+3

6+=+a%281%29%5E2+%2B+3

6+=+a+%2B+3

6-3+=+a

3+=+a

a+=+3
The leading coefficient is positive, so the parabola opens upward.

We have
y+=+a%28x-h%29%5E2+%2B+k
turn into
y+=+3%28x-1%29%5E2+%2B+3
after plugging in a = 3, h = 1, k = 3

We could expand things out and combine like terms like so
y+=+3%28x-1%29%5E2+%2B+3

y+=+3%28x%5E2-2x%2B1%29+%2B+3 FOIL rule

y+=+3x%5E2-6x%2B3+%2B+3 Distribute

y+=+3x%5E2-6x%2B9 Combine like terms

The vertex form y+=+3%28x-1%29%5E2+%2B+3 expands and simplifies to the standard form y+=+3x%5E2-6x%2B9

Graph:
+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+0%2C3%28x-1%29%5E2+%2B+3%29+
note the vertex is the lowest point at (1,3)