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The vertex of this parabola is at (4,-3). When the x-value is 5, the y-value is -6.What is the coefficient of the squared expression in the parabola's equation?

User Marleny
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2 Answers

3 votes

Final Answer:

The coefficient of the squared expression in the parabola's equation is -3.

Step-by-step explanation:

We can solve this problem by using the vertex form of the parabola equation:

y = a(x - h)^2 + k

where:

a is the coefficient of the squared term

h is the x-coordinate of the vertex

k is the y-coordinate of the vertex

We are given that:

h = 4 (from the vertex coordinates)

k = -3 (from the vertex coordinates)

Now, we can use the additional information that the parabola passes through the point (5, -6). Substituting these values into the equation, we get:

-6 = a(5 - 4)^2 - 3

Solving for a:

-6 = a(1)^2 - 3

-6 = a - 3

-3 = a

Therefore, the coefficient of the squared term, a, is -3.

User MinTwin
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2 votes

Answer:


-3x^(2)+24x-51

Step-by-step explanation:

we have that the form of the parabola's equation is


ax^(2)+bx+c

an also we have


a(4)^(2)+b(4)+c=-3\\a(5)^(2)+b(5)+c=-6

and for the vertex in (4,-3)


x=-(b)/(2a)


4=-(b)/(2a)\\b=-8a (1)

if we subtract the first equation to the second equation we can obtain a 2x2 system equation


9a+b=-3\\b=-3-9a (2)

and by taking the equations (1) and (2)


-8a=-3-9a\\a=-3

hence, for b we have


b=-8(a)=-8(-3)=24

and to compute c we can use


a(4)^(2)+b(4)+c=-3\\(-3)(16)+(24)(4)+c=-3\\c=-51

Finally we have that the parabola is


-3x^(2)+24x-51

I hope this is useful for you

regards

User Jim Blum
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