Q. A parabola opening up or down has vertex (0,−1) and passes through (−12,17). Write its equation in vertex form.Simplify any fractions.
Vertex Form of Parabola: What is the vertex form of the parabola?The vertex form of a parabola is given by the equation y=a(x−h)2+k, where (h,k) is the vertex of the parabola.
Equation with Vertex: What is the equation of a parabola with a vertex at (0,−1)?Substitute 0 for h and −1 for k in the vertex form.y=a(x−0)2+(−1)y=ax2−1
Use Point to Find a: Use the point (−12,17) to find the value of a. Replace the variables with (−12,17) in the equation. Substitute −12 for x and 17 for y. 17=a(−12)2−117=144a−1
Solve for a: Solve for a.Add 1 to both sides of the equation.17+1=144a18=144aDivide both sides by 144.14418=aSimplify the fraction.81=a
Write Equation with a: Write the equation of the parabola using the value of a. Substitute 81 for a in the equation y=ax2−1. y=(81)x2−1 Vertex form of the parabola: y=(81)x2−1
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