SOLUTION: Find the quadratic function that fits the set of data points. (-3,-5), (-2,-8), (6,-248) Possibille answers: A) f(x)=3x2 + 18x - 5 B) f(x)= -3x2 + 3x - 5 C) f(

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Find the quadratic function that fits the set of data points. (-3,-5), (-2,-8), (6,-248) Possibille answers: A) f(x)=3x2 + 18x - 5 B) f(x)= -3x2 + 3x - 5 C) f(      Log On


   

Question 721664: Find the quadratic function that fits the set of data points.

(-3,-5), (-2,-8), (6,-248)
Possibille answers:
A) f(x)=3x2 + 18x - 5
B) f(x)= -3x2 + 3x - 5
C) f(x)= -3x2 - 18x -32
D) f(x)= -2x2 + 18x + 32
E) None
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

(x,y)=(-3,-5), (-2,-8), (6,-248) plug in values for x and y=f%28x%29 and find out what equation will be true
Possibille answers:
A) f%28x%29=3x%5E2+%2B+18x+-+5...for (x,y)=(-3,-5)
-5=3%28-3%29%5E2+%2B+18%28-3%29+-+5
-5=3%2A9+-54+-+5
-5=27+-59
-5=-32....pair (-3,-5) is not solution
B) f%28x%29=+-3x%5E2+%2B+3x+-+5...for (x,y)=(-3,-5)
-5=+-3%28-3%29%5E2+%2B+3%28-3%29+-+5
-5=+-3%2A9-9+-+5
-5=+-27-9-+5
-5=+-41....pair (-3,-5) is not solution


C) f%28x%29=+-3x%5E2+-+18x+-32...for (x,y)=(-3,-5)
-5=+-3%28-3%29%5E2+-+18%28-3%29+-32
-5=+-27+%2B+54+-32
-5=+-59+%2B+54+
-5=+-5+..........pair (-3,-5) is solution
check the second pair
f%28x%29=+-3x%5E2+-+18x+-32...for (x,y)=(-2,-8)
-8=+-3%28-2%29%5E2+-+18%28-2%29+-32
-8=+-12+%2B+36+-32
-8=+-44+%2B+36+
-8=+-8+..........pair (-2,-8) is solution
check the third pair
f%28x%29=+-3x%5E2+-+18x+-32...for (x,y)=(6,-248)
-248=+-3%286%29%5E2+-+18%286%29+-32
-248=+-3%2A36+-108+-32
-248=+-108+-108+-32
-248=+-248+..........pair (6,-248) is solution
so, the quadratic function that fits the set of data points (-3,-5), (-2,-8), (6,-248) is C) f%28x%29=+-3x%5E2+-+18x+-32
you do not have to check:
D) f%28x%29=+-2x%5E2+%2B+18x+%2B+32
E) None