Hi
Re: Do I have to solve the equation first to find the max nos to input into the calculator so I can see the graph.
using: y = ax^2 +bx + 2 = a(x - (-b/2a))^2...as in Completing the Square...
one could find that 180/9.8 is the x-value of the maximum point
and then yes find f(180/9.8) to find the y-value of that maximum point
Note: the vertex form of a Parabola opening Up(a>0) or Down(a<0)is 
where(h,k) is the vertex and line of symmetry is x = h
The equation is: h=-4.9t^2+180t+2 where h is the height and t is time.
Thank you
h=-4.9t^2+180t+2
Yes, one can use a graphing Calculator (using x in place of t)
As to sizing... 1st derivative tells us Maxmimun is at ~18 (180/9.8) which results in height of 1600+
Using -100,2000 for y-axis and -60,60 for the x - axis, one can take a look at it
