Write the equation of the quadratic function given the three points on the function. Write the equation in standard form f(x)=ax2+bx+c. (0,−12), (1,−9), (−2,−36)
Q. Write the equation of the quadratic function given the three points on the function. Write the equation in standard form f(x)=ax2+bx+c. (0,−12), (1,−9), (−2,−36)
Find c: Plug in the first point (0,−12) into the standard form equation to find c.f(x)=ax2+bx+c−12=a(0)2+b(0)+cc=−12
Relationship between a and b: Plug in the second point (1,−9) into the standard form equation to find a relationship between a and b. −9=a(1)2+b(1)+c −9=a+b−12 a+b=3
Another relationship between a and b: Plug in the third point (−2,−36) into the standard form equation to find another relationship between a and b.−36=a(−2)2+b(−2)+c−36=4a−2b−124a−2b=−24
Solve system of equations: Solve the system of equations from the second and third steps to find a and b.a+b=34a−2b=−24Multiply the first equation by 2 and add to the second equation.2a+2b=64a−2b=−246a=−18a=−3
Find b: Substitute a=−3 into the first equation to find b.−3+b=3b=6
Write final equation: Write the final equation using the values of a, b, and c.f(x)=ax2+bx+cf(x)=−3x2+6x−12
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