Find the range of the function.

ƒ (x) = 2x^2 + 7

1) The minimum value of f (x) is going to be when x=0,

f (0) = 7, all others positive and negative values give f (x) >7.

2) Coefficient near x² is positive, so parabola is "up".

So range is f (x) ≥7, or (7,+∞).