How do you identify the important parts of #y= 2x^2+7x-21# to graph it?
y intercept = -21 ; shape is an upward horse shoe with the minimum at
equation standard form is
in this case:
So this an upwards with a minimum y value but goes on increasing from there to infinity.
y intercept at
which is the value of the constant c.
The value of
the correction is to compensate for the constant we have introduced. We still have the -21 but we have introduced
Now we look inside the brackets at the
The minimum occurs at