Precalculus Examples

$\cos (\frac{- 4 π}{2})$

Step 1

Cancel the common factor of $- 4$ and $2$ .

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Step 1.1

Factor $2$ out of $- 4 π$ .

$\cos (\frac{2 (- 2 π)}{2})$

Step 1.2

Cancel the common factors.

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Step 1.2.1

Factor $2$ out of $2$ .

$\cos (\frac{2 (- 2 π)}{2 (1)})$

Step 1.2.2

Cancel the common factor.

$\cos (\frac{2 (- 2 π)}{2 \cdot 1})$

Step 1.2.3

Rewrite the expression.

$\cos (\frac{- 2 π}{1})$

Step 1.2.4

Divide $- 2 π$ by $1$ .

$\cos (- 2 π)$

Step 2

Add full rotations of $2 π$ until the angle is greater than or equal to $0$ and less than $2 π$ .

$\cos (0)$

Step 3

The exact value of $\cos (0)$ is $1$ .

$1$