 # How Do I Find The Line Of Symmetry?

## What is a parabola equation?

The directrix is a line that is ⊥ to the axis of symmetry and lies “outside” the parabola (not intersecting with the parabola).

y = ax2 + bx + c from your study of quadratics.

And, of course, these remain popular equation forms of a parabola.

The vertex is (0,0), the focus is (0,¼), and the directrix is y = -¼..

## What is the meaning of line of symmetry?

A line of symmetry is a line that cuts a shape exactly in half. This means that if you were to fold the shape along the line, both halves would match exactly. Equally, if you were to place a mirror along the line, the shape would remain unchanged. A square has 4 lines of symmetry, as shown below.

## What is a line of symmetry on a graph?

The axis or line of symmetry is an imaginary line that runs through the center of a line or shape creating two perfectly identical halves. In higher level mathematics, you will be asked to find the axis of symmetry of a parabola. This is a parabola, a u-shaped line on the graph.

## What is the axis of symmetry examples?

The two sides of a graph on either side of the axis of symmetry look like mirror images of each other. Example: This is a graph of the parabola y = x2 – 4x + 2 together with its axis of symmetry x = 2. The axis of symmetry is the red vertical line.

## What is the formula to find the axis of symmetry?

If the vertex of a parabola is (k,l), then its axis of symmetry has equation x=k. We can find a simple formula for the value of k in terms of the coefficients of the quadratic. As usual, we complete the square: y=ax2+bx+c=a[x2+bax+ca]=a[(x+b2a)2+ca−(b2a)2].

## Which shape has 2 lines of symmetry?

rectangleA shape can have more than one line of symmetry. Thus a rectangle has two lines of symmetry, an equilateral triangle has three lines of symmetry, and a square has four. A circle has an infinite number of lines of symmetry since it can be folded about any diameter.

## What are the 4 types of symmetry?

The four main types of this symmetry are translation, rotation, reflection, and glide reflection.

## Which figure has 2 lines of symmetry?

RectangleRectangle. A rectangle has two lines of symmetry. It has rotational symmetry of order two.

## How do you find the line of symmetry of a quadratic equation?

The axis of symmetry always passes through the vertex of the parabola . The x -coordinate of the vertex is the equation of the axis of symmetry of the parabola. For a quadratic function in standard form, y=ax2+bx+c , the axis of symmetry is a vertical line x=−b2a .

## How do you find the line of symmetry of a parabola?

When a quadratic function is graphed in the coordinate plane, the resulting parabola and corresponding axis of symmetry are vertical. The graph of the parabola represented by the quadratic function y = a( x – p )2 + q has an axis of symmetry represented by the equation of the vertical line x = p.