Algebra Examples

$y = {(x - 1)}^{2}$

Step 1

Find the properties of the given parabola.

Tap for more steps...

Step 1.1

Use the vertex form, $y = a {(x - h)}^{2} + k$ , to determine the values of $a$ , $h$ , and $k$ .

$a = 1$

$h = 1$

$k = 0$

Step 1.2

Since the value of $a$ is positive, the parabola opens up.

Opens Up

Step 1.3

Find the vertex $(h, k)$ .

$(1, 0)$

Step 1.4

Find $p$ , the distance from the vertex to the focus.

Tap for more steps...

Step 1.4.1

Find the distance from the vertex to a focus of the parabola by using the following formula.

$\frac{1}{4 a}$

Step 1.4.2

Substitute the value of $a$ into the formula.

$\frac{1}{4 \cdot 1}$

Step 1.4.3

Cancel the common factor of $1$ .

Tap for more steps...

Step 1.4.3.1

Cancel the common factor.

$\frac{1}{4 \cdot 1}$

Step 1.4.3.2

Rewrite the expression.

$\frac{1}{4}$

Step 1.5

Find the focus.

Tap for more steps...

Step 1.5.1

The focus of a parabola can be found by adding $p$ to the y-coordinate $k$ if the parabola opens up or down.

$(h, k + p)$

Step 1.5.2

Substitute the known values of $h$ , $p$ , and $k$ into the formula and simplify.

$(1, \frac{1}{4})$

Step 1.6

Find the axis of symmetry by finding the line that passes through the vertex and the focus.

$x = 1$

Step 1.7

Find the directrix.

Tap for more steps...

Step 1.7.1

The directrix of a parabola is the horizontal line found by subtracting $p$ from the y-coordinate $k$ of the vertex if the parabola opens up or down.

$y = k - p$

Step 1.7.2

Substitute the known values of $p$ and $k$ into the formula and simplify.

$y = - \frac{1}{4}$

Step 1.8

Use the properties of the parabola to analyze and graph the parabola.

Direction: Opens Up

Vertex: $(1, 0)$

Focus: $(1, \frac{1}{4})$

Axis of Symmetry: $x = 1$

Directrix: $y = - \frac{1}{4}$

Direction: Opens Up

Vertex: $(1, 0)$

Focus: $(1, \frac{1}{4})$

Axis of Symmetry: $x = 1$

Directrix: $y = - \frac{1}{4}$

Step 2

Select a few $x$ values, and plug them into the equation to find the corresponding $y$ values. The $x$ values should be selected around the vertex.

Tap for more steps...

Step 2.1

Replace the variable $x$ with $0$ in the expression.

$f (0) = {(0)}^{2} - 2 \cdot 0 + 1$

Step 2.2

Simplify the result.

Tap for more steps...

Step 2.2.1

Simplify each term.

Tap for more steps...

Step 2.2.1.1

Raising $0$ to any positive power yields $0$ .

$f (0) = 0 - 2 \cdot 0 + 1$

Step 2.2.1.2

Multiply $- 2$ by $0$ .

$f (0) = 0 + 0 + 1$

Step 2.2.2

Simplify by adding numbers.

Tap for more steps...

Step 2.2.2.1

Add $0$ and $0$ .

$f (0) = 0 + 1$

Step 2.2.2.2

Add $0$ and $1$ .

$f (0) = 1$

Step 2.2.3

The final answer is $1$ .

$1$

Step 2.3

The $y$ value at $x = 0$ is $1$ .

$y = 1$

Step 2.4

Replace the variable $x$ with $- 1$ in the expression.

$f (- 1) = {(- 1)}^{2} - 2 \cdot - 1 + 1$

Step 2.5

Simplify the result.

Tap for more steps...

Step 2.5.1

Simplify each term.

Tap for more steps...

Step 2.5.1.1

Raise $- 1$ to the power of $2$ .

$f (- 1) = 1 - 2 \cdot - 1 + 1$

Step 2.5.1.2

Multiply $- 2$ by $- 1$ .

$f (- 1) = 1 + 2 + 1$

Step 2.5.2

Simplify by adding numbers.

Tap for more steps...

Step 2.5.2.1

Add $1$ and $2$ .

$f (- 1) = 3 + 1$

Step 2.5.2.2

Add $3$ and $1$ .

$f (- 1) = 4$

Step 2.5.3

The final answer is $4$ .

$4$

Step 2.6

The $y$ value at $x = - 1$ is $4$ .

$y = 4$

Step 2.7

Replace the variable $x$ with $2$ in the expression.

$f (2) = {(2)}^{2} - 2 \cdot 2 + 1$

Step 2.8

Simplify the result.

Tap for more steps...

Step 2.8.1

Simplify each term.

Tap for more steps...

Step 2.8.1.1

Raise $2$ to the power of $2$ .

$f (2) = 4 - 2 \cdot 2 + 1$

Step 2.8.1.2

Multiply $- 2$ by $2$ .

$f (2) = 4 - 4 + 1$

Step 2.8.2

Simplify by adding and subtracting.

Tap for more steps...

Step 2.8.2.1

Subtract $4$ from $4$ .

$f (2) = 0 + 1$

Step 2.8.2.2

Add $0$ and $1$ .

$f (2) = 1$

Step 2.8.3

The final answer is $1$ .

$1$

Step 2.9

The $y$ value at $x = 2$ is $1$ .

$y = 1$

Step 2.10

Replace the variable $x$ with $3$ in the expression.

$f (3) = {(3)}^{2} - 2 \cdot 3 + 1$

Step 2.11

Simplify the result.

Tap for more steps...

Step 2.11.1

Simplify each term.

Tap for more steps...

Step 2.11.1.1

Raise $3$ to the power of $2$ .

$f (3) = 9 - 2 \cdot 3 + 1$

Step 2.11.1.2

Multiply $- 2$ by $3$ .

$f (3) = 9 - 6 + 1$

Step 2.11.2

Simplify by adding and subtracting.

Tap for more steps...

Step 2.11.2.1

Subtract $6$ from $9$ .

$f (3) = 3 + 1$

Step 2.11.2.2

Add $3$ and $1$ .

$f (3) = 4$

Step 2.11.3

The final answer is $4$ .

$4$

Step 2.12

The $y$ value at $x = 3$ is $4$ .

$y = 4$

Step 2.13

Graph the parabola using its properties and the selected points.

$\begin{array}{c} x & y \\ - 1 & 4 \\ 0 & 1 \\ 1 & 0 \\ 2 & 1 \\ 3 & 4 \end{array}$

Step 3

Graph the parabola using its properties and the selected points.

Direction: Opens Up

Vertex: $(1, 0)$

Focus: $(1, \frac{1}{4})$

Axis of Symmetry: $x = 1$

Directrix: $y = - \frac{1}{4}$

$\begin{array}{c} x & y \\ - 1 & 4 \\ 0 & 1 \\ 1 & 0 \\ 2 & 1 \\ 3 & 4 \end{array}$

Step 4