Alright
First, you rearrange it into f(x + 1) = f(x) - x^2, I swapped the order cause it is easier to work with
f(3) = f(2 + 1) = 7
Now from the f(x+1) equation you can say f(2 + 1) = f(2) - 2^2 = 7
f(2) - 4 = 7
so f(2) = 11
f(2) = f(1 + 1) = 11
From the f(x + 1) function again, f(1 + 1) =...
Dude, I have this one friend who got like Ds and Es in year 11 but managed to get early entry into some 95 atar comp sci course at Wollongong with a scholarship. I think you will be fine. Make sure to apply though.
My teachers told me to do 4 hours a day as well
I got too lazy to do it, it is harder than it seems
Although if you do manage to do it then you would do quite well I think.