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A problem contains the points (0,0),(1,-2) and (-1,-4). What is the equation of this parabola in standard form?

User Lfk
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1 Answer

9 votes

Answer:

The general equation of the parabola y = -3 x² + x

Explanation:

Step(i):-

Given points are (0,0) , (1, -2) and ( -1 , -4 )

Given the standard parabola

y = ax²+ b x + c ...(i)

Passing through the point (0,0)

c = 0

Passing through the point (1,-2)

-2 = a(1) +b(1)

a + b = -2 ...(ii)

Passing through the point (-1, -4)

- 4 = a - b

a - b = -4 ...(iii)

Step(ii):-

Adding (ii) and (iii) equations , we get

2 a = -6

a = - 3

substitute a = - 3 in equation (ii)

-3 + b =-2

b = -2 + 3 = 1

Final answer:-

The general equation of the parabola

y = ax²+ b x + c

y = -3 x² + x + 0

y = -3 x² + x

User Chrisgonzalez
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