Hello Caleb
1) when Find the y-intercept just plug 0 for x; y = 4 - 0^2 -8*0 = 4
2) when Find the vertex follow these:
- Get the equation in the form y = a*x^2 + b*x + c.
- Calculate -b / 2a. This is the x-coordinate of the vertex.
- To find the y-coordinate of the vertex, simply plug the value of -b / 2a into the equation for x and solve for y.
if you need more assistance please let me know