1) To find the y-intercept, x should be equal to zero
2) To find x intercept, y should be equal to zero. To find x intercepts in quadratic equations you can use the formula
x = (-b±√b^2-4*a*c)/2*a
3) Vertex here you find with this formula x = -b/2a (your equation is of the form ax^2+bx+c). After you ave obtained your x value from this formula, just input it into your original equation to obtain the y value of vertex
So,
1) y = 0^2-6*0+8 = 0-0+8 = 8 (y intercept is at 8)
2) x = (-(-6)±√(-6)^2-4*1*8)/2*1 = (6±√4)/2 = (6+2)/2 and (6-2)/2 = 4 and 2 (c intercepts are at 4 and 2)
3) x = (-(-6))/2*1 = 3
y = 3^2-6*3+8 = 9-18+8 = -1 (vertex has coordinates (3,-1))
