# college algebra

posted by alli

graph the function and state the vertex axis of symmetry, the intercepts, if any: f(x)=x^2-8x+15

Please show work so i can understand this. thank you

1. Henry

F(x) = Y = x^2 - 8x + 15.

h = Xv = -B/2A = 8 / 2 = 4.
K = Yv = 4^2 - 8*4 + 15 = -1.
V(h,k) = V(4,-1).

Axis = h = 4.

The intercepts are the value of X when
Y = 0:
Y = x^2 - 8x + 15 = 0
C = 15 = (-1)*(-15) = (-3)*(-5).
We select -3 and -5 for factoring because the sum = B(-8).
(x-5)(x-3) = 0
x-5 = 0
X = 5.
x-3 = 0
X = 3.
Intercepts(Solution set): X = 5, and 3.

To graph the function, select values of X below and above h; and calculate the
corresponding value of Y.

(x,y). Y = x^2 - 8x + 15.
(1,8).
(2,3).
(3,0).
V(4,-1).
(5,0).
(6,3).
(7,8).

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