Q. A parabola opening up or down has vertex (0,−5) and passes through (−4,−3). Write its equation in vertex form.Simplify any fractions.
Vertex Form: 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 at Vertex: What is the equation of a parabola with a vertex at (0,−5)?Substitute 0 for h and −5 for k in the vertex form.y=a(x−0)2+(−5)y=ax2−5
Use Point to Find a: Use the point (−4,−3) to find the value of a. Replace the variables with (−4,−3) in the equation. Substitute −4 for x and −3 for y. −3=a(−4)2−5−3=16a−5
Solve for a: Solve for a.−3=16a−5Add 5 to both sides of the equation.2=16aDivide both sides by 16.162=aSimplify the fraction.81=a
Write Equation with a: Write the equation of the parabola with the value of a. Substitute 81 for a in the equation y=ax2−5. y=(81)x2−5 Vertex form of the parabola: y=(81)x2−5
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