There is no graphing problem that you'll be asked to solve before university that can't be plotted to a 'good enough for high school' level by hand in seconds.
Four data points is sufficient to give you a 'good enough' shape and position of a second-degree polynomial. Five or six for a third-degree one. (And you barely see them, and don't learn how to algebraically solve for their roots in high school anyways, because the cubic factoring formula is a pig.)
If you can't tell what a function's plotted shape is going to be at a glance, you haven't learned the material to the degree expected of an attentive child.
There is no graphing problem that you'll be asked to solve before university that can't be plotted to a 'good enough for high school' level by hand in seconds.
Four data points is sufficient to give you a 'good enough' shape and position of a second-degree polynomial. Five or six for a third-degree one. (And you barely see them, and don't learn how to algebraically solve for their roots in high school anyways, because the cubic factoring formula is a pig.)
If you can't tell what a function's plotted shape is going to be at a glance, you haven't learned the material to the degree expected of an attentive child.