Trigonometry Examples

$\frac{x^{2}}{9} - \frac{y^{2}}{7} = 1$

Step 1

Simplify each term in the equation in order to set the right side equal to $1$ . The standard form of an ellipse or hyperbola requires the right side of the equation be $1$ .

$\frac{x^{2}}{9} - \frac{y^{2}}{7} = 1$

Step 2

This is the form of a hyperbola. Use this form to determine the values used to find vertices and asymptotes of the hyperbola.

$\frac{{(x - h)}^{2}}{a^{2}} - \frac{{(y - k)}^{2}}{b^{2}} = 1$

Step 3

Match the values in this hyperbola to those of the standard form. The variable $h$ represents the x-offset from the origin, $k$ represents the y-offset from origin, $a$ .

$a = 3$

$b = \sqrt{7}$

$k = 0$

$h = 0$

Step 4

The center of a hyperbola follows the form of $(h, k)$ . Substitute in the values of $h$ and $k$ .

$(0, 0)$

Step 5

Find $c$ , the distance from the center to a focus.

Tap for more steps...

Step 5.1

Find the distance from the center to a focus of the hyperbola by using the following formula.

$\sqrt{a^{2} + b^{2}}$

Step 5.2

Substitute the values of $a$ and $b$ in the formula.

$\sqrt{{(3)}^{2} + {(\sqrt{7})}^{2}}$

Step 5.3

Simplify.

Tap for more steps...

Step 5.3.1

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

$\sqrt{9 + {(\sqrt{7})}^{2}}$

Step 5.3.2

Rewrite ${\sqrt{7}}^{2}$ as $7$ .

Tap for more steps...

Step 5.3.2.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{7}$ as $7^{\frac{1}{2}}$ .

$\sqrt{9 + {(7^{\frac{1}{2}})}^{2}}$

Step 5.3.2.2

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$\sqrt{9 + 7^{\frac{1}{2} \cdot 2}}$

Step 5.3.2.3

Combine $\frac{1}{2}$ and $2$ .

$\sqrt{9 + 7^{\frac{2}{2}}}$

Step 5.3.2.4

Cancel the common factor of $2$ .

Tap for more steps...

Step 5.3.2.4.1

Cancel the common factor.

$\sqrt{9 + 7^{\frac{2}{2}}}$

Step 5.3.2.4.2

Rewrite the expression.

$\sqrt{9 + 7^{1}}$

Step 5.3.2.5

Evaluate the exponent.

$\sqrt{9 + 7}$

Step 5.3.3

Simplify the expression.

Tap for more steps...

Step 5.3.3.1

Add $9$ and $7$ .

$\sqrt{16}$

Step 5.3.3.2

Rewrite $16$ as $4^{2}$ .

$\sqrt{4^{2}}$

Step 5.3.3.3

Pull terms out from under the radical, assuming positive real numbers.

$4$

Step 6

Find the vertices.

Tap for more steps...

Step 6.1

The first vertex of a hyperbola can be found by adding $a$ to $h$ .

$(h + a, k)$

Step 6.2

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

$(3, 0)$

Step 6.3

The second vertex of a hyperbola can be found by subtracting $a$ from $h$ .

$(h - a, k)$

Step 6.4

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

$(- 3, 0)$

Step 6.5

The vertices of a hyperbola follow the form of $(h \pm a, k)$ . Hyperbolas have two vertices.

$(3, 0), (- 3, 0)$

Step 7

Find the foci.

Tap for more steps...

Step 7.1

The first focus of a hyperbola can be found by adding $c$ to $h$ .

$(h + c, k)$

Step 7.2

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

$(4, 0)$

Step 7.3

The second focus of a hyperbola can be found by subtracting $c$ from $h$ .

$(h - c, k)$

Step 7.4

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

$(- 4, 0)$

Step 7.5

The foci of a hyperbola follow the form of $(h \pm \sqrt{a^{2} + b^{2}}, k)$ . Hyperbolas have two foci.

$(4, 0), (- 4, 0)$

Step 8

Find the eccentricity.

Tap for more steps...

Step 8.1

Find the eccentricity by using the following formula.

$\frac{\sqrt{a^{2} + b^{2}}}{a}$

Step 8.2

Substitute the values of $a$ and $b$ into the formula.

$\frac{\sqrt{{(3)}^{2} + {(\sqrt{7})}^{2}}}{3}$

Step 8.3

Simplify the numerator.

Tap for more steps...

Step 8.3.1

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

$\frac{\sqrt{9 + {\sqrt{7}}^{2}}}{3}$

Step 8.3.2

Rewrite ${\sqrt{7}}^{2}$ as $7$ .

Tap for more steps...

Step 8.3.2.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{7}$ as $7^{\frac{1}{2}}$ .

$\frac{\sqrt{9 + {(7^{\frac{1}{2}})}^{2}}}{3}$

Step 8.3.2.2

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$\frac{\sqrt{9 + 7^{\frac{1}{2} \cdot 2}}}{3}$

Step 8.3.2.3

Combine $\frac{1}{2}$ and $2$ .

$\frac{\sqrt{9 + 7^{\frac{2}{2}}}}{3}$

Step 8.3.2.4

Cancel the common factor of $2$ .

Tap for more steps...

Step 8.3.2.4.1

Cancel the common factor.

$\frac{\sqrt{9 + 7^{\frac{2}{2}}}}{3}$

Step 8.3.2.4.2

Rewrite the expression.

$\frac{\sqrt{9 + 7^{1}}}{3}$

Step 8.3.2.5

Evaluate the exponent.

$\frac{\sqrt{9 + 7}}{3}$

Step 8.3.3

Add $9$ and $7$ .

$\frac{\sqrt{16}}{3}$

Step 8.3.4

Rewrite $16$ as $4^{2}$ .

$\frac{\sqrt{4^{2}}}{3}$

Step 8.3.5

Pull terms out from under the radical, assuming positive real numbers.

$\frac{4}{3}$

Step 9

Find the focal parameter.

Tap for more steps...

Step 9.1

Find the value of the focal parameter of the hyperbola by using the following formula.

$\frac{b^{2}}{\sqrt{a^{2} + b^{2}}}$

Step 9.2

Substitute the values of $b$ and $\sqrt{a^{2} + b^{2}}$ in the formula.

$\frac{{\sqrt{7}}^{2}}{4}$

Step 9.3

Rewrite ${\sqrt{7}}^{2}$ as $7$ .

Tap for more steps...

Step 9.3.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{7}$ as $7^{\frac{1}{2}}$ .

$\frac{{(7^{\frac{1}{2}})}^{2}}{4}$

Step 9.3.2

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$\frac{7^{\frac{1}{2} \cdot 2}}{4}$

Step 9.3.3

Combine $\frac{1}{2}$ and $2$ .

$\frac{7^{\frac{2}{2}}}{4}$

Step 9.3.4

Cancel the common factor of $2$ .

Tap for more steps...

Step 9.3.4.1

Cancel the common factor.

$\frac{7^{\frac{2}{2}}}{4}$

Step 9.3.4.2

Rewrite the expression.

$\frac{7^{1}}{4}$

Step 9.3.5

Evaluate the exponent.

$\frac{7}{4}$

Step 10

The asymptotes follow the form $y = \pm \frac{b (x - h)}{a} + k$ because this hyperbola opens left and right.

$y = \pm \frac{\sqrt{7}}{3} x + 0$

Step 11

Simplify $\frac{\sqrt{7}}{3} x + 0$ .

Tap for more steps...

Step 11.1

Add $\frac{\sqrt{7}}{3} x$ and $0$ .

$y = \frac{\sqrt{7}}{3} x$

Step 11.2

Combine $\frac{\sqrt{7}}{3}$ and $x$ .

$y = \frac{\sqrt{7} x}{3}$

Step 12

Simplify $- \frac{\sqrt{7}}{3} x + 0$ .

Tap for more steps...

Step 12.1

Add $- \frac{\sqrt{7}}{3} x$ and $0$ .

$y = - \frac{\sqrt{7}}{3} x$

Step 12.2

Combine $x$ and $\frac{\sqrt{7}}{3}$ .

$y = - \frac{x \sqrt{7}}{3}$

Step 13

This hyperbola has two asymptotes.

$y = \frac{\sqrt{7} x}{3}, y = - \frac{x \sqrt{7}}{3}$

Step 14

These values represent the important values for graphing and analyzing a hyperbola.

Center: $(0, 0)$

Vertices: $(3, 0), (- 3, 0)$

Foci: $(4, 0), (- 4, 0)$

Eccentricity: $\frac{4}{3}$

Focal Parameter: $\frac{7}{4}$

Asymptotes: $y = \frac{\sqrt{7} x}{3}$ , $y = - \frac{x \sqrt{7}}{3}$

Step 15