SOLUTION: Please help me solve the following per step. Thanks! For the quadratic function: f(x)=x^2-4x-5 find: a) y-intercept b) x-intercept(s) c) the vertex d) f(6)

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Please help me solve the following per step. Thanks! For the quadratic function: f(x)=x^2-4x-5 find: a) y-intercept b) x-intercept(s) c) the vertex d) f(6)      Log On


   

Question 930050: Please help me solve the following per step. Thanks!
For the quadratic function: f(x)=x^2-4x-5 find:
a) y-intercept
b) x-intercept(s)
c) the vertex
d) f(6)
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
y = x^2-4x-5 (x = 0)...y=intercept: -5
0 = (x+1)(x-5)
x-intercepts: -1, 5
.......
y = x^2-4x-5 (Completing the Square)
y = x^2-4x+4 -4 +5 = (x-2)^2 - 4 - 5
y = (x-2)^2 - 9 V(2,-9)
......
f(6) = (6)^2 - 4(6) - 5 = 7
.....
the vertex form of a Parabola opening up(a>0) or down(a<0),
y=a%28x-h%29%5E2+%2Bk
where(h,k) is the vertex and x = h is the Line of Symmetry
.....