If the equation of a quadratic is y = 6x2 -4x - 1, then the equation of the axis of symmetry is:

x= -1/3
x= 1/3
x=3
x=-3

Question

If the equation of a quadratic is y = 6x2 -4x - 1, then the equation of the axis of symmetry is: 

x= -1/3
x= 1/3
x=3
x=-3

mathstudent55 · Answer

$y = ax^2 + bx + c$

$y' = 2ax + b$

$2ax + b = 0$

$2ax = -b$

$x = -\dfrac{b}{2a} $

Now use the a and b of your problem to find x.

anonymous · Answer

so its -1/3?

anonymous · Answer

$$y=6\left( x ^{2}-\frac{ 4 }{6 }x \right)-1$$
$$y=6\left( x ^{2} -\frac{ 1 }{ 3 }x+\frac{ 1 }{ 9 }-\frac{ 1 }{9 }\right)-1$$
$$y=6\left( x-\frac{ 1 }{ 3 } \right)^{2}-\frac{ 6 }{ 9 }-1$$
$$y=6\left( x-\frac{ 1 }{ 3 } \right)^{2}-\frac{ 5 }{ 3 }$$
$$axis is x-\frac{ 1 }{3 }=0,or x=\frac{ 1 }{3 }$$

mathstudent55 · Answer

$x = -\dfrac{b}{2a} $

$x = -\dfrac{(-4)}{2(6)} $

$x = \dfrac{4}{12} $

$ x = \dfrac{1}{3} $

anonymous · Answer

ohh ok that makes sense now

mathstudent55 · Answer

great