How do you identify the important parts of #f(x)= 2x^2 - 11# to graph it?

1 Answer
Sep 23, 2015

Any quadratic equation of form #y=ax^2+bx+c# has a parabola graph.

If a is positive (like here a = 2) then the arms go up.

In this case, c = -11 and represents the y-intercept.

The roots or x-intercepts of the equation are when y = 0, So in this case when #2x^2-11=0 => x= + or -sqrt(11/2)#

The axis of symmetry is at #x=(-b)/(2a)=0# in this case.

Then you can combine it all to draw the graph.

graph{2x^2-11 [-25.66, 25.65, -12.83, 12.83]}