Q. A parabola opening up or down has vertex (0,−1) and passes through (8,−5). Write its equation in vertex form.Simplify any fractions.
Vertex Form Explanation: 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 (8,−5) to find the value of 'a'.Replace the variables with (8,−5) in the equation.Substitute 8 for x and −5 for y.−5=a(8)2−1−5=64a−1
Solve for 'a': Solve for a. Add 1 to both sides of the equation to isolate the term with 'a'. −5+1=64a−1+1−4=64a Divide both sides by 64 to solve for 'a'. −4/64=a−1/16=a
Write Equation in Vertex Form: Write the equation of the parabola in vertex form using the value of a. Substitute −161 for a in the equation y=ax2−1. y=(−161)x2−1 The vertex form of the parabola is y=−161x2−1.
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