thanks for that link , so i've just attempted a graph looks like a squiggly line lol.
I was just curious, i can write f(x) = 15 - x - x^2
or y = 15 - x - x^2
Is that ok then i just make a table with my x values and substitue them ionto the equation to find each value of y for any given x value?
To graph this, you could rewrite in vertex form:
Since the leading coefficient was negative, the parabola opens downward. The vertex is given as (h, k), so it's . You can also find the x- and y- intercepts to get additional points.