SOLUTION: Sketch the graph of the function below. Please plot at least 5 points and show the complete solution. f(x)= -2x^2+4x

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Sketch the graph of the function below. Please plot at least 5 points and show the complete solution. f(x)= -2x^2+4x      Log On


   

Question 1090824: Sketch the graph of the function below. Please plot at least 5 points and show the complete solution.
f(x)= -2x^2+4x
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=+-2x%5E2%2B4x
choose values for x, calculate f%28x%29 or y (it is same), and make table
x|y
-2|-16 ->f%28-2%29=+-2%28-2%29%5E2%2B4%28-2%29=-2%2A4-8=-8-8=-16
-1|-6 ->f%28-1%29=+-2%28-1%29%5E2%2B4%28-1%29=-2%2A1-4=-2-4=-6
0|0 ->f%280%29=+-2%280%29%5E2%2B4%280%29=0%2B0=0
1|2 ->f%281%29=+-2%281%29%5E2%2B4%281%29=-2%2B4=2
2|0 ->f%282%29=+-2%282%29%5E2%2B4%282%29=-2%2A4%2B8=-8%2B8=0
3|-6 ->f%283%29=+-2%283%29%5E2%2B4%283%29=-2%2A9%2B12=-18%2B12=-6
plot these points and draw a line: