Determine the roots and axis of symmetry for the following q
Determine the root(s) and axis of symmetry for the following quadratic functions. Enter your answer as a single number of a string of numbers. Separate multiple answers with commas and if there are no roots write DNE. (For example, if the roots are 3 and 4 enter 3,4).
Solution
f(x) = x^2 +x -1
y = x^2 +x -1
y = x^2 +x +1/4 -1/4 -1
y = (x+1/2)^2 - 5/4
Vertex ( -1/2 , -5/4)
Parabola is upward facing , so the axis of symmetry : x = -1/2
Roots: x^2 +x -1 =0
x = (-1+/sqrt(1+4))/2
= -1.618 , 0.618
g(x) = (x+10(5x -1)
Roots : g(x) =0
x= -10 , x=1/5
Rewriting the equation : g(x) = 5x^2 +50x-x -10 = 5x^2 +49x -10
vertex of g(x) : x =-b/2a ; y = g(-b/2a)
x = -49/10 , y =-2601/20)
Upward facing parabola , Axis of symmetry : x = -49/10
h(x) = x^2 -x -42
Roots: h(x) =0
x^2 -x -42 =0
x = -6 ; x = 7
Vertex : x =-b/2a ; y = h(-b/2a)
x = 1/2 , y = -169/4
upward facing parabola , axis of symmetry : x = 1/2
