Question 1829
You have to substitute in the x,y values you know into the general equation of a quadratic (parabola), which is {{{y = ax^2 + bx + c}}} and then solve the 3 equation to find the 3 unknowns, a,b,c. Tedious but not difficult...

{{{ 1 = 9a + 3b + c}}}
{{{ 3 = 4a + 2b + c}}}
{{{-5 = c}}}

the third equation helps enormously...we know c!. Put this into the first 2 equations and find a and b.

You can do that :-). Don't forget to write out the equation, once you know the values of a, b and c!.

cheers
jon