Write the equation of the parabola that passes through the points (−1,0), (4,0), (5,−18) Write your answer in the form y=a(x–p)(x–q), where a, p, and q are integers, decimals, or simplified fractions.
Q. Write the equation of the parabola that passes through the points (−1,0), (4,0), (5,−18) Write your answer in the form y=a(x–p)(x–q), where a, p, and q are integers, decimals, or simplified fractions.
Identify p and q: Step 1: Identify the values of p and q from the given points where the parabola crosses the x-axis, which are (−1,0) and (4,0). Thus, p=−1 and q=4.
Use standard form: Step 2: Use the standard form of the equation for a parabola with these intercepts: y=a(x−p)(x−q). Substituting p=−1 and q=4, we get y=a(x+1)(x−4).
Substitute third point: Step 3: Substitute the third point (5,−18) into the equation to find 'a'. Plugging in x=5 and y=−18, we get −18=a(5+1)(5−4).
Simplify equation: Step 4: Simplify the equation from Step 3: −18=a(6)(1), which simplifies to −18=6a. Solving for a gives a=−18/6=−3.
Substitute value of a: Step 5: Substitute the value of a back into the equation from Step 2. We get y=−3(x+1)(x−4).
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