Posted by Ceedee on .
how do I graph the quadratic function in intercept form for y=(x+3)(x5)

Algebra I 
Steve,
you can see the xintercepts right off. They are the roots: 3 and 5
As for the yintercept, that is just 15
For excellent graphing help visit
http://rechneronline.de/functiongraphs/
and type in your function, but express all operators explicitly:
(x+3)*(x5)
To get a better picture, increase the x range to 10 to 10 and the yrange to 20 to 20