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Write a formula for quadratic function if its graph has the vertex at point (−2,5) and passes through the point (3,−10).

User Keaton
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2 Answers

3 votes

Answer:

Basically it's the expanded version of the person who already answered. It's -3/5(x)^2-12/5 x+ 13/5

User Tada
by
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6 votes

Answer:

The formula for the quadratic function is
y=5 - (3)/(5) \left(x + 2\right)^(2).

Explanation:

The quadratic function with vertex
(h,k) is given by
y=a \left(- h + x\right)^(2) + k.

We know that the vertex is
(-2,5). Thus, the formula for the quadratic function is


y=a \left(x + 2\right)^(2) + 5

To find
a, use the fact that the quadratic function passes through the point
\left(3, -10\right) and we solve for
a.


-10=a \left(3 + 2\right)^(2) + 5\\a\left(3+2\right)^2+5=-10\\5^2a+5=-10\\25a+5=-10\\25a=-15\\(25a)/(25)=(-15)/(25)\\a=-(3)/(5)

Thus, the formula for the quadratic function is
y=5 - (3)/(5) \left(x + 2\right)^(2).

User MikeyBeLike
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5.8k points