Algebra Examples

$f (x) = \sqrt{x^{2} - 4}$ ; at $x = - 5$

Step 1

Replace the variable $x$ with $- 5$ in the expression.

$f (- 5) = \sqrt{{(- 5)}^{2} - 4}$

Step 2

Simplify the result.

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Step 2.1

Raise $- 5$ to the power of $2$ .

$f (- 5) = \sqrt{25 - 4}$

Step 2.2

Subtract $4$ from $25$ .

$f (- 5) = \sqrt{21}$

Step 2.3

The final answer is $\sqrt{21}$ .

$\sqrt{21}$

Step 3

The result can be shown in multiple forms.

Exact Form:

$\sqrt{21}$

Decimal Form:

$4.58257569 \dots$

Step 4