also how would I graph this with my ti-89?
x = y - y^2
This is the inverse function of a parabola. Consider the following equation:
The vertex is: V(h, k)
And the need for p is to know if the function opens lefts or opens right (since this is an inverse of a parabola). Basically, if p>0, it opens right. If p<0, it opens left.
Now, first, we have to complete the square:
Rearrange the equation first:
Take -1 as common factor:
Complete the square:
Take -1/4 out by multiplying it with -1:
Factor the completed square:
Does this equation look familiar?
Ha ! I found the problem !!!
You have to take negative values of y.
So in the window (diamond F2), configurate the t.
Here is what I've done :
tmin=-10
tmax=10
tstep=.1
xmin=-10
xmax=10
xscl=1
ymin=-10
ymax=10
yscl=1
When you graph it, you can increase the speed by increasing tstep (to .5 for example).
Then, the usual stuff, when you're in the graph window, do F2 - A to get an automatic zoom