Find algebraically the equation of the axis of symmetry and the coordinates of the vertex of the parabola whose equation is y= -2x-8x+3

User Icon for Damon Damon answered
14 years ago

-2x^2-8x = y -3 (suspect you meant

x^2 + 4x = -(1/2)y +3/2
x^2 + 4x + 4 = -(1/2)y +11/2
(x+2)^2 = -(1/2) (y-11)
vertex at (-2,11) axis is x = -2

User Icon for Explain Bot Explain Bot answered
1 year ago

To find the equation of the axis of symmetry and the coordinates of the vertex of the parabola, you need to rewrite the given equation in the standard form of a quadratic equation, which is y = ax^2 + bx + c.

In this case, the given equation is y = -2x^2 - 8x + 3. To rewrite it in the standard form, you need to group the x terms together and rearrange the equation:

y = (-2x^2 - 8x) + 3
= -2x^2 - 8x + 3

Now, to find the axis of symmetry, you can use the formula x = -b / 2a. The coefficient b is the coefficient of x (in this case -8), and a is the coefficient of x^2 (which is -2). Plugging these values into the formula:

x = -(-8) / (2 * -2)
= 8 / -4
= -2

So, the equation of the axis of symmetry is x = -2.

To find the coordinates of the vertex, you substitute the value of x = -2 into the equation and solve for y:

y = -2(-2)^2 - 8(-2) + 3
= -2(4) + 16 + 3
= -8 + 16 + 3
= 11

Therefore, the coordinates of the vertex are (-2, 11).

In summary, the equation of the axis of symmetry is x = -2, and the coordinates of the vertex are (-2, 11).

User Icon for Step-by-Step Bot Step-by-Step Bot answered
1 year ago

To find the equation of the axis of symmetry and the coordinates of the vertex of the parabola whose equation is y = -2x^2 - 8x + 3, we can use the formula:

Axis of symmetry (x-coordinate of the vertex) = -b / 2a

where a, b, and c are the coefficients of the equation in the form ax^2 + bx + c.

In this case, a = -2 and b = -8. Plugging these values into the formula, we have:

Axis of symmetry (x-coordinate of the vertex) = -(-8) / 2(-2)
= 8 / -4
= -2

So, the equation of the axis of symmetry is x = -2.

To find the y-coordinate of the vertex, we substitute the x-coordinate of the vertex (-2) back into the equation:

y = -2(-2)^2 - 8(-2) + 3
= -2(4) + 16 + 3
= -8 + 19
= 11

Therefore, the coordinates of the vertex are (-2, 11).