SOLUTION: Find the equation of the quadratic function with zeros 10 and 12 and vertex at (11, -2) 1. y=2x^2-44x+120 2. y=2x^2-44x-240 3. y=2x^2-44x+240 4. y=-2x^2-44x+240

Algebra ->  College  -> Linear Algebra -> SOLUTION: Find the equation of the quadratic function with zeros 10 and 12 and vertex at (11, -2) 1. y=2x^2-44x+120 2. y=2x^2-44x-240 3. y=2x^2-44x+240 4. y=-2x^2-44x+240       Log On


   

Question 1066107: Find the equation of the quadratic function with zeros 10 and 12 and vertex at (11, -2)
1. y=2x^2-44x+120
2. y=2x^2-44x-240
3. y=2x^2-44x+240
4. y=-2x^2-44x+240
Answer by Edwin McCravy(20066) About Me  (Show Source):
You can put this solution on YOUR website!
Substitute the vertex (x,y) = (11,-2) into each one

1. y=2x²-44x+120 
  -2=2(11)²-44(11)+120
  -2=2(121)-484+120
  -2=242-484+120
  -2=-122
False, so 1 is eliminated

2. y=2x²-44x-240
  -2=2(11)²-44(11)-240
  -2=2(121)-484-240
  -2=242-484-240
  -2=-482
False, so 2 is eliminated


3. y=2x²-44x+240
  -2=2(11)²-44(11)+240
  -2=2(121)-484+240
  -2=242-484+240
  -2=-2
True, so 3 is possible

4. y=-2x²-44x+240
  -2=-2(11)²-44(11)+240
  -2=-2(121)-484+240
  -2=-242-484+240
  -2=-486
False, so 4 is eliminated

So the only possibility is 3.

Lots of times, eliminating the incorrect choices is
easier than solving the problem.

Edwin