Question

What is the line of symmetry of the parabola y=x2+6x-9?

x=6
x=-9
x=-3

Answer 1

Answer:

In the given parabola  $y=x^2+6x-9$  the line of symmetry is the axis x  = -3

Step-by-step explanation:

Here, the given equation of the parabola is : $y=x^2+6x-9$

Now, in the Standard Form of the Parabolic Equation: $y=ax^2+bx+c$,

The axis of symmetry is a vertical line x  = −b / 2 a .

Now, here comparing the given parabolic equation with teh standard form, we get  :  

a  = 1 , b = 6 and c  = -9

So, the axis of symmetry =  $-\frac{b}{2a}  =- \frac{6}{2(1)} =  -3$

Hence, here in the given parabola  $y=x^2+6x-9$  the line of symmetry is the axis x  = -3.